List of acronyms: A

(Main list of acronyms)


 * a – (s) Atto-
 * A – (s) Ampere

A0–9

 * A1C – Airman First Class
 * A2ATD or A2ATD – (i) Anti-Armour Advanced Technology Demonstration
 * A2C2 or A2C2 – (i) Army Airspace Command and Control
 * A3 – many, including a European larger than standard office paper size
 * A4 – many, including a European standard office paper size; see entry
 * A10 – (i) Atlantic 10 Conferencee

AA

 * aa – (s) Afar language (ISO 639-1 code)
 * aA – (s) Attoampere
 * AA
 * (i) achieved availability
 * Alcoholics Anonymous
 * (s) Armed Forces Americas (postal symbol)
 * Aruba (FIPS 10-4 territory code)
 * (i) assembly area
 * Automobile Association
 * avenue of approach
 * American Airlines
 * Aerolíneas Argentinas
 * AAA
 * (i) administration, authorization, and authentication
 * American Automobile Association ("Triple-A")
 * anti-aircraft artillery
 * Amateur Athletic Association (of England)
 * Asistencia Asesoría y Administración (Spanish, "Assistance, Consulting, and Administration" — original name of Mexican professional wrestling promotion Lucha Libre AAA Worldwide)
 * AAAI – (i) Association for the Advancement of Artificial Intelligence, formerly American Association for Artificial Intelligence
 * AAAS – (i) American Association for the Advancement of Science
 * AAAV – (i) Advanced Amphibious Assault Vehicle
 * AABN – (i) African Aurora Business Network
 * AABP – (i) American Association of Bovine Practitioners
 * AAC
 * (i) American Athletic Conference
 * Army Air Corps (British Army)
 * AACL – (i) Albanian American Civic League
 * AACCS – (i) American Association of Christian Colleges and Seminaries
 * AAD
 * (i) analogue-analogue-digital (CD quality)
 * Australian Antarctic Division
 * AADHD – Adult attention deficit hyperactivity disorder
 * AADT – (i) annual average daily traffic
 * AADAC – (a) Alberta Alcohol and Drug Abuse Commission
 * AADC
 * (i) area air defense commander
 * (i) amino acid decarboxylase
 * (i) aromatic L-amino acid decarboxylase
 * (i) Australian Antarctic Data Centre
 * AAFC
 * (i) U.S. Army Air Corps Ferrying Command (1941–1942)
 * All-America Football Conference (1946–1949)
 * AAFES – (i) Army and Air Force Exchange Service
 * AAI – (i) applied artificial intelligence
 * AAIS – (i) advanced airborne interceptor simulator
 * AAM – (i) air-to-air missile
 * AAMOF – (i) as a matter of fact
 * AAN – (i) American Academy of Nursing
 * AANEAS – (a) Anglo-Australian Near-Earth Asteroid Survey
 * AAODL – (i) Atmospheric Aerosols and Optics Data Library
 * a.a.p. – (i) Associated Artists Productions (former film distributor)
 * AAP
 * (i) advanced acquisition plan
 * Allied administrative publication
 * American Academy of Pediatrics
 * AAPC – (i) Accounting and Auditing Policy Committee
 * aar – (s) Afar language (ISO 639-2 code)
 * AAR
 * (i) after-action review
 * Association of American Railroads
 * AARP – (i/s) American Association of Retired Persons (now officially known only by the initials)
 * AAS
 * (i) Advanced Automation System
 * American Astronomical Society ("double-A-S")
 * AASPEM – (i) advanced air-to-air system performance evaluation model
 * AAT – (i) Australian Antarctic Territory
 * AAV – (i) Amphibious Assault Vehicle
 * AAWC – (i) anti-air warfare commander

AB

 * ab – (s) Abkhaz language (ISO 639-1 code)
 * AB
 * (i) Able Seaman (both the rank and the occupation)
 * (s) Alberta (postal symbol)
 * ABA
 * (i) Adriatic Basketball Association
 * American Bar Association
 * American Basketball Association
 * American Beverage Association
 * American Bicycle Association
 * American Birding Association
 * Australian Broadcasting Authority
 * ABB – (i) ASEA Brown Boveri (Swiss-Swedish multinational company)
 * ABBA – (a) Agnetha, Benny, Björn, Anni-Frid (Swedish pop group)
 * ABC
 * (i) abstinence, be faithful, condoms
 * Active Body Control
 * airway, breathing, circulation (see CPR)
 * Alcoholic Beverage Control (or Alcoholic Beverage Commission)
 * alien big cat
 * always be careful
 * American Bird Conservancy
 * American-born Chinese
 * American Broadcasting Company
 * anti-lock brake controller
 * Associated British Cinemas
 * ABC Cinemas
 * ABC Weekend TV (Associated British Cinemas (Television) Ltd / ABC Television Ltd)
 * Associated British Corporation (ABC Television Films Ltd)
 * Atanasoff–Berry Computer
 * Atlantic Baptist College
 * atomic, biological, chemical (see NBC)
 * Australian Broadcasting Corporation
 * already been chewed gum
 * ABCA
 * (i) American, British and Canadian Armies (originally)
 * Army Bureau of Current Affairs
 * ABCS – (i) (U.S.) Army Battle Command System
 * ABET – (a) Accreditation Board for Engineering and Technology
 * ABFIST – (i) Advanced Bradley Full Crew Interactive Skills Trainer
 * ABGI – (i) Addington-Barker Group International
 * ABIN – (a) Agência Brasileira de Inteligência (Brazilian Intelligence Agency)
 * abk – (s) Abkhaz language (ISO 639-2 code)
 * ABL – (i) American Basketball League
 * ABLE
 * (a) Achieving a Better Life Experience Act, a U.S. law that established tax-advantaged accounts for the benefit of individuals with disabilities
 * AirBorne Law Enforcement (police air support unit)
 * ABM – (i) anti-ballistic missile – Asynchronous Balanced Mode – automated banking machine
 * ABMC – (i) American Battle Monuments Commission
 * ABN
 * (i) Australian Business Number (a number issued by the Australian government as registration of a business and used for taxation purposes)
 * Advance Beneficiary Notice of Non-coverage (a form used in health insurance)
 * ABPI – (i) Association of the British Pharmaceutical Industry
 * ABRSM – (a) Associated Board of the Royal Schools of Music
 * ABS
 * (i) acrylonitrile butadiene styrene
 * anti-lock braking system
 * ABSA – (a) Amalgamated Banks of South Africa ("ab-sa")
 * ABSTRIPS – (p) abstraction-based STRIPS
 * ABV – (i) Alcohol by volume
 * ABW – (s) Aruba (ISO 3166 trigram)

AC

 * aC – (s) Attocoulomb
 * Ac – (s) Actinium
 * AC
 * (i) Adriamycin-Cyclophosphamide (chemotherapy)
 * Air Conditioning
 * Aircraftman
 * Alternating Current
 * Altocumulus
 * ante Christum (Latin, "before Christ"; see BC)
 * ante cibum (Latin, "before meals")
 * (s) Antigua and Barbuda (FIPS 10-4 country code)
 * (i) Associazione Calcio (Italian, "football (soccer) club")
 * A/C – (i) Air Conditioned/Conditioning – Aircraft
 * AC1 – Aircraftman 1st Class
 * AC2 – Aircraftman 2nd Class
 * ACA
 * Affordable Care Act, shorthand for the Patient Protection and Affordable Care Act, commonly called "Obamacare"
 * (i) Airspace Control Authority
 * Airspace Co-ordination Area
 * A Current Affair
 * ACAB, short for "All Cops Are Bastards"; used as a political slogan associated with dissidents who are opposed to the police.
 * ACARS – (a) Aircraft Communications Addressing and Reporting System
 * ACAS
 * (a) Aboriginal Children's Advancement Society
 * Advisory, Conciliation and Arbitration Service
 * ACB – (i) Asociación de Clubes de Baloncesto (Spanish for "Association of Basketball Clubs")
 * ACC
 * (i) U.S. Air Combat Command
 * Air Component Commander
 * Alpine Club of Canada
 * Altocumulus castellanus
 * Area control center
 * Atlantic Coast Conference
 * Automatic climate control
 * ACCA
 * (i) The Association of Chartered Certified Accountants
 * Automatic Cloud Cover Assessment
 * ACCAC – (a) Awdurdod Cymwysterau, Cwricwlwm ac Asesu Cymru (Qualifications, Curriculum and Assessment Authority for Wales)
 * ACCD – American Coalition of Citizens with Disabilities
 * ACCS – (i) Air Communications and Control Squadron
 * ACDA – (i) Arms Control & Disarmament Agency
 * ACDC
 * (i) Alternating Current Direct Current
 * the name of an Australian rock music band
 * a term for a bisexual person
 * A/Cdre – Air Commodore
 * ACDT
 * (a) Apple Certified Desktop Technician
 * (a) Australian Central Daylight Time
 * ACE
 * (a) Air Combat Emulator (computer game)
 * Allied Command Europe
 * Angiotensin-converting enzyme
 * Armored Combat Earthmover
 * Automatic Computing Engine
 * ACE2 – (i/p) Angiotensin-converting enzyme 2 (pronounced "ace-two")
 * ACES
 * (a) Aerolíneas Centrales de Colombia (Spanish, "Central Colombian Airlines")
 * Auxiliary Campus Enterprises and Services of Alfred State College
 * ACF
 * (i) Administration for Children and Families
 * American Car and Foundry
 * American Culinary Federation
 * ACH – (i) Automated clearing house
 * ACHT – (i) Average Call Hold Time
 * ACID – (a) Atomicity, Consistency, Isolation, and Durability (in databases)
 * ACINT – (p) Acoustic Intelligence
 * ACK – (p) Acknowledge (telecommunications; cf. NAK)
 * ACL
 * (i) Access Control List
 * Anterior cruciate ligament; the initialism can also refer to an injury to this ligament
 * Atlantic Coast Line Railroad
 * ACLJ – (i) American Center for Law and Justice
 * ACLOS – (i) Automatic CLOS (missile control system)
 * ACLS – (i) American Council of Learned Societies
 * ACLU
 * (i) American Civil Liberties Union
 * American Communist Lawyers Union (pejorative slang for the above)
 * ACM – many, including Association for Computing Machinery; see entry
 * ACMC – (i) (U.S.) Assistant Commandant of the Marine Corps
 * ACN
 * (i) Airborne Communications Node
 * Australian Company Number (number issued by the Australian government as registration of a limited liability company)
 * ACNA – (i) Anglican Church in North America
 * ACO – (i) Airspace Control Order
 * ACOBA – (a) Advisory Committee on Business Appointments
 * ACOG – (a) American College of Obstetricians and Gynecologists
 * ACOM – (p) (U.S.) Atlantic Command
 * ACORN – (a) Association of Community Organizations for Reform Now
 * ACP
 * (i) African, Caribbean and Pacific Group of States
 * Air Control Point
 * ACR – (i) Advanced Concepts and Requirements
 * ACRI – (p) African Crisis Response Initiative
 * ACRT – (i) Advanced Concepts Research Tool simulator
 * ACS
 * (i) Affiliated Computer Services (NYSE ACS)
 * Alaska Communications Service
 * American Cancer Society
 * American Chemical Society
 * Association of Caribbean States
 * Australian Computer Society
 * ACSC – (i) Army Command and Staff College (various nations)
 * ACST – (i) Australian Central Standard Time
 * ACST – (i) American Cooperative School of Tunis
 * ACT
 * (i) Adaptive Control of Thought (cognitive model)
 * American College Test (ing Program)
 * Australian Capital Territory (also postal symbol)
 * ACT UP – (a) AIDS Coalition to Unleash Power
 * ACTD – (i) Advanced Concept Technology Demonstration
 * ACTF
 * (i) (U.S.) Army Constructive Training Federation
 * Australian Children's Television Foundation
 * ACT-R – (i) ACT-Rational (cognitive model)
 * ACT-R/PM – (i) ACT-R/Perceptual-Motor (cognitive model)
 * ACTU – (i) Australian Council of Trade Unions
 * ACU
 * (i) Abilene Christian University
 * American Conservative Union
 * ACUF
 * (i) BGN Advisory Committee on Undersea Features
 * (a) American Conservative Union Foundation
 * ACV – (i) Armoured Combat Vehicle

AD

 * AD – (i) Air Defence – (s) Andorra (ISO 3166 digram) – (i) Anno Domini (Latin, "In the year of our Lord")
 * A/D – (i) Analog/Digital
 * ADA
 * (i) Air Defence Artillery
 * American Dental Association
 * Assistant District Attorney
 * Americans with Disabilities Act (see also the similar but non-acronymic Ada programming language)
 * ADA Cryptocurrency token for Cardano blockchain
 * ADAC – (a/i) Allgemeiner Deutscher Automobil-Club (German, "General German Automobile Club")
 * ADAGE – (a) Air Defense Air to Ground Engagement (simulation)
 * ADAP – (i) AIDS Drug Assistance Program
 * ADAS – (a/i) Asiago-DLR Asteroid Survey
 * ADAT – (i) Alesis Digital Audio Tape (recording format)
 * ADatP – (p) Automated Data Processing
 * ADATS –
 * (i) Agricultural Development and Training Society
 * Air Defence Anti-Tank System
 * Australian Defence Air Traffic System
 * ADB – (i) Asian Development Bank
 * ADB- All da best/All the best - texting slang
 * ADC –
 * (i) Aide De Camp
 * U.S. Air Defense Command (1946–1992)
 * Apple Display Connector
 * ADCTS – (i) Advanced Distributed Combat Training System
 * ADD –
 * (i) Analog Digital Digital (CD quality)
 * Attention-Deficit Disorder
 * Administration on Developmental Disabilities
 * ADDIE – (i) Analyze Design Develop Implement and Evaluate
 * ADDNS – (i) Advanced Deployable Day/Night Simulation
 * ADE
 * (i) Algebraic differential equation
 * Antibody-dependent enhancement
 * ADF
 * (i) Australian Defence Force
 * African Development Foundation
 * ADGB – Air Defence of Great Britain
 * ADHD – (i) Attention-Deficit Hyperactivity Disorder
 * ADHS – (i) Attention-Deficit Hyperactivity Syndrome
 * ADI – (i) Acceptable/Allowable Daily Intake
 * ADIZ – (a/i) Air Defence Identification Zone
 * ADL – (i) Anti-Defamation League
 * ad loc. – (p) ad locum (Latin, "to/at the place")
 * ADM –
 * (i) Administrative
 * (s) Admiral, and the U.S. Public Health Service Commissioned Corps
 * Archer Daniels Midland
 * Assistant Deputy Minister
 * ADOA – (a/i) Air Defence Operations Area
 * ADP –
 * (i) Adenosine DiPhosphate
 * Army Doctrine Publication (UK, Canada, Australia)
 * Automatic/Automated Data Processing
 * ADRG – (p) Arc-second Raster Chart (ARC) Digitized Raster Graphics
 * ADS –
 * (a/i) Active Denial System
 * Astrophysics Data System
 * Attention Deficit Syndrome
 * ADSR – (i) Attack, Decay, Sustain, Release (sound envelope specification)
 * ADT
 * (i) Abu Dhabi Terminals, operator of commercial ports in Abu Dhabi
 * American District Telegraph, a former name of ADT Inc.
 * Atlantic Daylight Time (UTC−3 hours)
 * ADTB – (i) Army Doctrine and Training Bulletin
 * adv. – (p) adversus (Latin, "against")
 * ADW – (i) Air Defence Warning

AE

 * ae – (s) Avestan language (ISO 639-1 code)
 * AE
 * (s) Armed Forces Africa/Canada/Europe/Middle East (postal symbol)
 * United Arab Emirates (ISO 3166 digram; FIPS 10-4 country code)
 * (i) Artix Entertainment
 * American Eagle
 * A&E
 * (a/i) Arts & Entertainment Network, the original name for the U.S. TV channel now known as A&E Network
 * Accident and Emergency
 * AEB – Autonomous Emergency Braking, see Collision avoidance system
 * AED – (s) United Arab Emirates dirham (ISO 4217 currency code)
 * AEDT – (a) Australian Eastern Daylight Time
 * AEF – (i) American Expeditionary Force
 * AEGIS – (p) Airborne Early warning Ground environment Interface Segment (fake etymology)
 * AEI-T – (i) Army Enterprise Infostructure-Transport
 * aeq. – (p) aequalis (Latin, "equal")
 * AESR – (i) Aeronautical Equipment Service Record
 * AEST – (a) Australian Eastern Standard Time
 * aet. – (p) aetatis (Latin, "of age", "aged")
 * aet – (i) After extra time (Football)
 * AEW
 * (i) Air Expeditionary Wing
 * (i) Airborne early warning
 * (i) Airborne electronic warfare
 * (i) All Elite Wrestling (US professional wrestling promotion)

AF

 * af – (s) Afrikaans language (ISO 639-1 code)
 * aF – (s) Attofarad
 * AF
 * (s) Afghanistan (FIPS 10-4 country code; ISO 3166 digram)
 * (i) Air Force
 * As fuck
 * AFA
 * (i) U.S. Air Force Academy
 * Asociación del Fútbol Argentino (Spanish, "Argentine Football Association")
 * AFAIC – (i) As Far As I'm Concerned
 * AFAICT – (i) As Far As I Can Tell
 * AFAIK – (i) As Far As I Know
 * AFAIR – (i) As Far As I Remember/Recall
 * AFAM
 * (i/a) Associazione Friulana di Astronomia e Meteorologia (Italian, "Friuli Association of Astronomy and Meteorology")
 * (p) Department of African and Afro-American Studies, University of North Carolina at Chapel Hill — notable for its links to the school's academic-athletic scandal in the 2010s
 * AFATDS – (i) Advanced Field Artillery Tactical Data System
 * AFC
 * (i) American Football Conference
 * Approved for construction
 * Asian Football Confederation
 * AFCEA – (i) Armed Forces Communications and Electronics Association
 * AfD
 * (i) Allianz für Deutschland ("Alliance for Germany"), former political alliance in East Germany
 * Alternative für Deutschland ("Alternative for Germany"), current German political party
 * AFD
 * (i) Active Format Description, a technical standard for TV or set-top box decoders
 * Advanced Format Drive, a type of computing storage device
 * Adjustable-frequency drive
 * Adult Film Database, web-based database of adult cinema
 * Agence française de développement ("French Development Agency"), a French international development agency
 * Alliance des forces démocratiques (French; "Alliance of Democratic Forces"), an Ivorian political alliance
 * Alliance for Freedom and Democracy, an Eritrean political party
 * AFDB – (i) African Development Bank
 * AFES – (i) Automatic Fire Extinguishing System
 * AFG – (s) Afghanistan (ISO 3166 trigram)
 * AFGAM – (i) Amazon Facebook Google Apple Microsoft
 * AFI
 * (s) French Territory of the Afars and Issas (ISO 3166 trigram; obsolete since 1977)
 * (i) "Agencia Federal de Investigaciónes" (México)
 * AFIS
 * (a) Automated Fingerprint Identification System
 * American Forces Information Service
 * AFIST – (i) Abrams Full Crew Interactive Skills Trainer
 * AFJ – (i) April Fool's Joke
 * AFK – (i) Away From Keyboard (Internet chat abbreviation)
 * AFL
 * (i) American Federation of Labor
 * American Football League — either the 1960s league that merged into the National Football League, or one of several other leagues of American football
 * Arena Football League
 * Australian Football League
 * AFL–CIO – (i) American Federation of Labor – Congress of Industrial Organizations
 * AFLAC – (a) American Family Life Assurance Company of Columbus
 * AFM – (i) Army Field Manual (UK; the U.S. more frequently uses just FM) – Atomic Force Microscope – Aviation Fleet Maintenance
 * AFN – (s) Afghani (ISO 4217 currency code)
 * AFO – (i) Association of Field Ornithologists
 * AFOSR – (i) U.S. Air Force Office of Scientific Research
 * AFP
 * (i) Agence France-Presse (French, "French Press Agency")
 * Australian Federal Police
 * AFQT – (i) Armed Forces Qualification Test
 * afr – (s) Afrikaans language (ISO 639-2 code)
 * AFRC – (i) Air Force Reserve Command
 * AFRL – (i) Air Force Research Laboratory
 * AFROTC – (i) Air Force Reserve Officer Training Corps
 * AFRRI – (i, U.S.) Armed Forces Radiobiology Research Institute
 * AFRTS – (i) Armed Forces Radio and Television Service
 * AFS
 * (i) Active Front Steering
 * Air Facility Sub-System
 * Amniotic Fluid-derived Stem cell
 * AFS&A or AFSA – (i) U.S. Air Force Studies and Analysis
 * AFSC
 * (i) U.S. Air Force Staff College (obsolete; replaced by JFSC)
 * U.S. Air Force Systems Command
 * AFSCN – (i) U.S. Air Force Satellite Control Network
 * AFSPC – (i) Air Force Space Command
 * AFT – American Farmland Trust
 * AFV – (i) armoured fighting vehicle or America's Funniest Home Videos
 * AFWA
 * (a) Air Force Weather Agency
 * Association of Fish and Wildlife Agencies

AG

 * ag – (s) Attogram
 * Ag – (s) Silver (Latin argentum)
 * AG
 * (i) air gunner
 * Aktiengesellschaft (German, "incorporated")
 * (s) Algeria (FIPS 10-4 country code)
 * Antigua and Barbuda (ISO 3166 digram)
 * Assemblies of God
 * AGA
 * (a/i) AB Gas-accumulator ("ah-gah", Swedish company)
 * Advanced Graphics Architecture
 * AGARD – (a) Advisory Group for Aerospace Research and Development
 * AGARDograph – (p) Advanced Guidance for Alliance Research and Development publication
 * AGASA – (a) Akeno Giant Air Shower Array (cosmic ray detector)
 * AGB – (i) Internal Nintendo initialism (Advanced Game Boy) for Game Boy Advance
 * AGC
 * (i) Apollo Guidance Computer
 * Automatic Gain Control
 * AGC – (i) Adjutant General's Corps (British Army)
 * AGDC – (i) Australian Game Developers' Conference
 * AGI – (i) Auxiliary Group Intelligence
 * AGL – (i) Above Ground Level
 * AGM – (i) Annual General Meeting
 * AGN – (i) Active Galactic Nucleus
 * AGO – (s) Angola (ISO 3166 trigram)
 * AGP – (i) Accelerated Graphics Port
 * AGRICOLA – (a) Agriculture Online Access
 * AGS – (i) Alaska Ground Station (LandSat)
 * AGTS – (i) Advanced Gunnery Training System
 * AGU – (i) American Geophysical Union
 * AGW – (i) Autonomous Guided Weapon

AH

 * aH – (s) Attohenry
 * Ah – (s) Ampere hour
 * AH – (i) Attack Helicopter
 * AHA – (i) American Heart Association
 * AHCPR – (i) Agency for Health Care Policy and Research (obsolete; replaced with AHRQ)
 * AHEC – (i) Australian Health Ethics Committee
 * AHPCRC – (i) Army High Performance Computing Research Center
 * AHQ – Air Headquarters
 * AHRQ – (i) Agency for Healthcare Research and Quality
 * AHS – (i)	American Housing Survey

AI

 * AI
 * (i) Air Interdiction
 * Amnesty International
 * Artificial Insemination
 * Artificial Intelligence
 * (s) Anguilla (ISO 3166 digram)
 * AIA
 * (i) Aerospace Industries Association
 * American Institute of Architects
 * (s) Anguilla (ISO 3166 trigram)
 * AIAA – (i) American Institute of Aeronautics and Astronautics
 * AIC
 * (i) African Independent Church
 * Animal Identification Coordinator
 * AICD – (i) Australian Institute of Company Directors
 * AICMFP – (i) And I Claim My Five Pounds
 * AID – (i) U.S. Agency for International Development
 * AIDS – (a) Acquired Immune Deficiency Syndrome
 * AIHW – Australian Institute of Health and Welfare
 * AIM – many, including AOL Instant Messenger, Australian Institute of Management; see entry
 * AIMP – (i) Aurora Incremental Modernization Project
 * AIPAC – (i) American Israel Public Affairs Committee
 * AIR – (i) Aircraft Inventory Record
 * AIRFA – (a) American Indian Religious Freedom Act
 * AIRS – (a/i) Aerometric Information Retrieval System (obsolete; replaced with AFS)
 * AIS
 * (i) Australian Institute of Sport
 * Automatic Identification System
 * AISB – (i) (British) Society for the Study of Artificial Intelligence and the Simulation of Behaviour

AJ

 * aJ – (s) Attojoule
 * AJ – (s) Azerbaijan (FIPS 10-4 country code)
 * Ajax – (a) Asynchronous JavaScript And XML
 * AJD – (i) Astronomical Julian day
 * AJP – (i) Allied Joint Publication
 * AJPW – (i) All Japan Pro Wrestling

AK

 * ak – (s) Akan languages (ISO 639-1 code)
 * aK – (s) Attokelvin
 * AK – (s) Alaska (postal symbol)
 * aka – (s) Akan languages (ISO 639-2 code)
 * a.k.a. – (i) Also known as (i.e.: alias)
 * AKA – (i) Above knee amputation (orthopaedic usage)
 * AKDT – (p) Alaska Standard Daylight Saving Time (UTC−8 hours)
 * AKST – (p) Alaska Standard Time (UTC−9 hours)
 * AKP – (i) Adalet ve Kalkınma Partisi (Turkish, "Justice and Development Party")

AL

 * aL – (s) Attolitre
 * Al – (s) Aluminium
 * AL
 * (s) Alabama (postal symbol)
 * Albania (FIPS 10-4 country code; ISO 3166 digram)
 * (i) Anno Lucis (Latin, "Year of Light", in Masonic tradition, most often seen on plaques bearing the founding dates of buildings, in years AD and years AL)
 * ALA – (s) Åland (ISO 3166 trigram)
 * ALAP – (a) As Long/Late As Possible
 * ALARM – (a) Air-Launched Anti-Radar Missile
 * ALB – (s) Albania (ISO 3166 trigram)
 * ALCOA or Alcoa – The Aluminum Company of America, NYSE:AA
 * ALD – (i) Accounting Line Designator (nuclear weapon targeting)
 * ALERT – (a) Advanced Linked Extended Reconnaissance and Targeting – Attack and Launch Early Reporting to Theatre
 * ALF
 * (a) Africa Leadership Forum
 * Alien Life Form (cf. ALF (TV series))
 * Animal Liberation Front
 * ALG – (s) Algeria (IOC and FIFA trigram, but not ISO 3166)
 * ALGOL – (p) ALGOrithmic Language
 * ALL – (s) Albanian lek (ISO 4217 currency code)
 * ALOA – (i) Associated Locksmiths of America, Inc.
 * ALOC
 * (a) Air Lines Of Communication
 * (a) Average Length of Calls
 * ALP – (i) Australian Labor Party
 * ALPA – (a) Air Line Pilots Association
 * ALS – (i) Amyotrophic Lateral Sclerosis – Automatic Landing System
 * ALSHS – (a) Abraham Low Self-Help Systems
 * ALSP – (i) Aggregate Level Simulation Protocol
 * ALTA – American Land Title Association
 * ALTE – (a) Association of Language Testers in Europe
 * ALTACS – (p) Automated decision Logic Tactical Air Combat Simulation

AM

 * am
 * (s) Amharic language (ISO 639-1 code)
 * Attometre
 * Am – (s) Americium
 * AM
 * many, including Amplitude Modulation and Ante Meridiem; see entry
 * (s) Armenia (FIPS 10-4 country code; ISO 3166 digram)
 * AM1 – Airman 1st class
 * AMA
 * (i) American Medical Association
 * Australian Medical Association
 * AMAPS – (a) Aircraft, Missile, Avionics Performance Simulation
 * AMC
 * (i) Adaptive modulation and coding (digital communications)
 * U.S. Air Mobility Command
 * American Motors Corporation
 * American Movie Classics (TV network; now known simply by the initials)
 * U.S. Army Materiel Command
 * AMCB – (i) U.S. Army/Marine Corps Board
 * AMD
 * (i) Advanced Micro Devices
 * Age-related Macular Degeneration
 * (s) Armenian dram (ISO 4217 currency code)
 * AMF – (i) Afghan Military Force(s)
 * AMFOM – (i) Advanced Missile Fly Out Model ("am-fomm")
 * AMFR
 * (i) Age-specific Marital Fertility Rate
 * Amplitude Modulation Following Response
 * AMFRS
 * (i) Advanced Multi-Function Radio Frequency System
 * Automatic Multisensor Feature-based Recognition System
 * amh – (s) Amharic language (ISO 639-2 code)
 * AML – (i) Acute Myeloid Leukaemia
 * AMLCD – (i) Active Matrix Liquid Crystal Display
 * AMLO
 * (i) Andrés Manuel López Obrador (Mexican politician)
 * Anti-Money Laundering Office — separate government agencies in Taiwan and Thailand
 * AMO – (i) Atlantic Multidecadal Oscillation
 * AMOLED – (i) Active-matrix organic light-emitting diode
 * AMOS
 * (a) Advanced MOrtar System
 * Air Force Maui Optical and Supercomputing observatory
 * AMP
 * (i) Adenosine MonoPhosphate
 * Automated Mission Planner
 * Anak ng Puta
 * (i) Ain't My Problem
 * AMRAAM – (a) Advanced Medium-Range Air-to-Air Missile
 * AMRDEC – (i) U.S. Aviation & Missile Research, Development, & Engineering Center
 * AMS
 * (i) Agriculture Marketing Service
 * American Mathematical Society
 * AMSAA – (i/a) U.S. Army Materiel Systems Analysis Activity
 * AMSB – (i) Aix Maurienne Savoie Basket (French basketball club)
 * AMSO – (i/a) U.S. Army Model and Simulation Office
 * AMSU – Advanced Microwave Sounding Unit
 * AMTE – (i) UK Admiralty Marine Technology Establishment (1977–1984)

AN

 * an – (s) Aragonese language (ISO 639-1 code)
 * aN – (s) Attonewton
 * AN
 * (s) Andorra (FIPS 10-4 country code)
 * Netherlands Antilles (ISO 3166 digram)
 * ANA
 * (i) Administration for Native Americans
 * Afghan National Army
 * All Nippon Airways
 * Anti-Nuclear Anti-body
 * (a) Australian National Airways
 * Australian Natives' Association
 * ANC – (i) African National Congress
 * AND – (s) Andorra (ISO 3166 trigram)
 * ANFO – (i) Ammonium nitrate/fuel oil (explosive)
 * ANG
 * (i) Air National Guard
 * (s) Angola (IOC and FIFA trigram, but not ISO 3166)
 * (s) Netherlands Antillian guilder (ISO 4217 currency code)
 * ANGLiCo – (p) Air/Naval Gunfire Liaison Company
 * ANL – (i) Argonne National Laboratory
 * ANM – (i) Acoustic Noise Monitor
 * ANOVA – (p) ANalysis Of VAriance
 * ANS – (i) Applied and Natural Sciences
 * ANSI – (a) American National Standards Institute
 * ANTM – (i) America's Next Top Model
 * ANT
 * (s) Netherlands Antilles (ISO 3166 trigram)
 * Antigua and Barbuda (IOC trigram, but not ISO 3166 or FIFA)
 * ANTY – Acronyms, No Thank You
 * ANWA – (i) Augusta National Women's Amateur, a prominent American golf tournament
 * ANWR – (i) Arctic National Wildlife Refuge
 * ANZ – (s) Australia and New Zealand Banking Group
 * ANZAC – (a) Australian and New Zealand Army Corps

AO

 * AO
 * (s) Angola (FIPS 10-4 country code; ISO 3166 digram)
 * (i) Approach Officer (submarine)
 * Area of Operations
 * AOA
 * (i) Air Officer in charge of Administration
 * Argonne National Laboratory
 * (s) Angolan kwanza (ISO 4217 currency code)
 * (i) Award of Arms (heraldry)
 * Angle of Attack (fluid dynamics)
 * AOC
 * (i) Air Operations Centre
 * Air Officer Commanding
 * Alexandria Ocasio-Cortez (American politician)
 * AOC in C – Air Officer Commanding in Chief
 * AOD – (i) Adrenalin O.D. (punk rock band)
 * AOE – Area of Effect
 * AOI
 * (i) Angle of Incidence
 * Arab Organization for Industrialization
 * AOL – (i) America OnLine
 * AOR – (i) Area of Responsibility
 * AOSTH – (i) Adventures of Sonic the Hedgehog
 * AOTS – (i) Attack of the Show!
 * AOU – (i) American Ornithologists' Union

AP

 * AP
 * (i) Advanced Placement
 * Air Publication
 * (s) Andhra Pradesh (Indian state code)
 * (s) Armed Forces Pacific (postal symbol)
 * (i) Associated Press
 * Auto Pilot
 * APA –
 * (i) Acolytes Protection Agency (professional wrestling tag team)
 * American Psychiatric Association
 * American Psychological Association (see also APA style, a writing format developed by this body)
 * APB – (i) All Points Bulletin (police jargon)
 * APC
 * (i) Armoured Personnel Carrier
 * Armour Piercing Capped (ammunition)
 * APEC – (a) Asia Pacific Economic Cooperation
 * APCNR – (i) Armour-Piercing, Composite Non-Rigid (ammunition)
 * APCR – (i) Armour-Piercing, Composite Rigid (ammunition)
 * APDS – (i) Armour-Piercing, Discarding-Sabot (ammunition)
 * APEDS – (a) AMSAA Performance Estimates Data System
 * APEX – (p) Applied Physics Express
 * APFSDS – (i) Armour-Piercing, Fin-Stabilised, Discarding Sabot (ammunition)
 * APHA – (i) American Public Health Association
 * APHE – (i) Armour-Piercing, High Explosive (ammunition)
 * APHIS – (a) Animal and Plant Health Inspection Service
 * API – (i) Application Programming Interface
 * APL
 * (i) A Programming Language
 * Acute Promyeloid Leukaemia
 * Anti-Personnel Landmine
 * Applied Physics Laboratory (Johns Hopkins University)
 * APM – (i) Advanced Power Management
 * APNP – Advanced Practice Nurse Prescriber
 * APOD – (i) Aerial Port (Airport) Of Debarkation
 * APOE – (i) Aerial Port (Airport) Of Embarkation
 * APOLLO – (a) Apache Point Observatory Lunar Laser-ranging Operation
 * APP – (i) Allied Procedural Publication
 * APR – (i) Annual Percentage Rate
 * APS
 * (i) Advanced Photo System (cf. APS-C, an image sensor format based on the size of the original APS film frame)
 * American Physical Society
 * Antiphospholipid Antibody Syndrome

AQ

 * AQ
 * (i) AdventureQuest
 * (s) American Samoa (FIPS 10-4 territory code)
 * Antarctica (ISO 3166 digram)
 * (i) Automatic qualifier, a term used by U.S. sports media from 1998 to 2013 to refer to the six conferences whose champions automatically entered the now-defunct Bowl Championship Series of college football
 * AQIM – (i) Al-Qaeda in the Islamic Maghreb
 * AQPS – (i) Autre que pur-sang (French: "Other than Thoroughbred"), designation of a type of French racehorse

AR

 * ar – (s) Arabic language (ISO 639-1 code)
 * Ar – (s) Argon
 * AR
 * (s) Argentina (FIPS 10-4 country code; ISO 3166 digram)
 * Arkansas (postal symbol)
 * (i) ArmaLite Rifle (cf. ArmaLite AR-15 and AR-15 style rifle, both also referred to with the "AR" initialism)
 * Armour
 * (s) Arunachal Pradesh (Indian state code)
 * ara – (s) Arabic language (ISO 639-2 code)
 * ARAG – (a) Advanced Research and Assessment Group
 * ARB – (i) Administrative Review Board
 * ARBA – (a/i) Army Review Boards Agency
 * ARC
 * (i) Appalachian Regional Commission
 * Arc-second Raster Chart
 * (a) Association of Retarded Citizens, the original name of the organization now known as Arc of the United States
 * (i) Athletics–Recreation Center, an indoor arena at Valparaiso University
 * ARCA – (a) Automobile Racing Club of America
 * ARCENT – (p) United States Army Central Command
 * ARDA – (a) Advanced Research and Development Activity (became DTO 2006)
 * ARE
 * (i) UK Admiralty Research Establishment (1984–1991)
 * (s) United Arab Emirates (ISO 3166 trigram)
 * ARF – (i) ASEAN Regional Forum
 * arg – (s) Aragonese language (ISO 639-2 code)
 * ARG – (s) Argentina (ISO 3166 trigram)
 * ARH – (s) Armed Reconnaissance Helicopter
 * ARI
 * (i) Acute Respiratory Infection
 * U.S. Army Research Institute for the Behavioral and Social Sciences
 * ARL
 * (i) UK Admiralty Research Laboratory (1921–1977)
 * U.S. Army Research Laboratory
 * UIUC Aviation Research Laboratory
 * ARM
 * (a) Acorn RISC Machine, later Advanced RISC Machine (cf. Arm Ltd.)
 * Anti-Radiation Missile
 * Adjustable-rate mortgage
 * (s) Armenia (ISO 3166 trigram)
 * ARNet – (p) Acquisition Reform Network
 * AROTS – Australian Rare Or Threatened Species
 * ARP – (i) Address Resolution Protocol – Applied Research Programme
 * ARPA – (a) Advanced Research Projects Agency
 * ARRC – (i) ACE Rapid Reaction Corps
 * ARRF – (i) Allied Rapid Reaction Force
 * ARRL – (i) American Radio Relay League
 * ARS
 * (i) Agricultural Research Service
 * (s) Argentine peso (ISO 4217 currency code)
 * ARSC – (i) Arctic Region Supercomputing Center
 * ARSPACE – (p) U.S. Army Space Command
 * ART
 * (a) Adaptive Resonance Theory
 * Anti-Retroviral Therapy
 * ARTCC – (i) Air Route Traffic Control Center
 * ARWG – (i) Army Research Working Group ("are-wig")

AS

 * as
 * (i) Adult swim
 * (s) Assamese language (ISO 639-1 code)
 * Attosecond
 * aS – (s) Attosiemens
 * As – (s) Arsenic
 * AS
 * (s) American Samoa (postal symbol; ISO 3166 digram)
 * Australia (FIPS 10-4 country code)
 * Assam / Asom (Indian state code)
 * Advanced Subsidiary (Subsidiary version of Advanced Level, 'A'-Level)
 * AS – (i) ActionScript
 * A/S – (i) Anti-submarine
 * A&S – (i) Armament & Standardisation
 * ASA
 * (i) AcetylSalicylic Acid
 * American Standards Association
 * Army Security Agency
 * Atlantic Southeast Airlines
 * Alaska Airlines (ICAO code)
 * ASAP – (a) As Soon As Possible
 * ASARS
 * (a) Advanced Synthetic Aperture Radar System
 * Airborne Search and Rescue System
 * ASB – (i) Associated Student Body – Alternative Service Book (Church of England)
 * asbl – (i) association sans but lucratif (French "Non-profit organisation")
 * ASBO – (a) Antisocial Behavior Order
 * ASCAP – (a) American Society of Composers, Authors, and Publishers
 * ASCC
 * (i) Army Service Component Commander
 * Automatic Sequence Controlled Calculator
 * Air Standardization Coordinating Committee
 * ASCIET – (i) All Services Combat Identification Evaluation Team
 * ASCII – (a) American Standard Code for Information Interchange
 * ASC+T – (i) Anti Slip Control + Traction
 * ASD
 * (i) (U.S.) Assistant Secretary of Defense
 * Autism spectrum disorder
 * ASD(C3I) – (i) (U.S.) (Command, Control, Communications, & Intelligence)
 * ASD(FMP) – (i) (U.S.) Assistant Secretary of Defense (Force Management Policy)
 * ASD(HA) – (i) (U.S.) Assistant Secretary of Defense (Health Affairs)
 * ASD(ISA) – (i) (U.S.) Assistant Secretary of Defense (International Security Affairs)
 * ASD(ISP) – (i) (U.S.) Assistant Secretary of Defense (International Security Policy)
 * ASD(LA) – (i) (U.S.) Assistant Secretary of Defense (Legislative Affairs)
 * ASD(PA) – (i) (U.S.) Assistant Secretary of Defense (Public Affairs)
 * ASD(RA) – (i) (U.S.) Assistant Secretary of Defense (Reserve Affairs)
 * ASD(SO&HA) – (i) (U.S.) Assistant Secretary of Defense (Special Operations & Humanitarian Assistance)
 * ASD(SO/LIC) – (i) (U.S.) (Special Operations & Low-Intensity Conflict)
 * ASD(S&R) – (i) (U.S.) Assistant Secretary of Defense (Strategy & Requirements)
 * ASD(S&TR) – (i) (U.S.) Assistant Secretary of Defense (Strategy & Threat Reduction)
 * ASDIC – (a) Allied Submarine Detection Investigation Committee (Sonar)
 * ASEAN – (a) Association of Southeast Asian Nations
 * ASFAR – (a) Americans for a Society Free of Age Restrictions
 * ASG – (i) Area Support Group
 * ASIC – (a) Australian Securities & Investments Commission – (a) Aviation Security Identification Card
 * ASICS – (a) Anima sana in corpore sano (Latin, "A sound mind in a sound body") (athletic shoe manufacturer)
 * ASIO
 * (a) Australian Security Intelligence Organisation
 * Audio Stream Input/Output
 * ASIP
 * (i) Advanced System Improvement Program
 * Army Stationing and Installation Plan
 * Application-specific instruction set processor
 * ASL
 * (i) Above Sea Level
 * American Sign Language (also known as Ameslan)
 * "Age, Sex, Location?" (Internet slang)
 * asm – (s) Assamese language (ISO 639-2 code)
 * ASM
 * (i) Air-to-Surface Missile
 * (s) American Samoa (ISO 3166 trigram)
 * (i) American Society for Metals
 * American Society for Microbiology
 * Association Sportive Montferrandaise (French, "Clermont-Ferrand Sporting Association"), as in ASM Clermont Auvergne
 * ASMB
 * (i) American Society for Matrix Biology
 * Adult Swim Message Board
 * ASME
 * (i) American Society of Mechanical Engineers
 * American Society of Magazine Editors
 * ASMP
 * (i) Air-Sol Moyenne Portée missile (French "Medium-range air to surface")
 * (p) Asymmetric multiprocessing
 * ASMR – Autonomous Sensory Meridian Response
 * ASN – (i) Associate of Science in Nursing
 * ASOC
 * (a/i) Air Sovereignty Operations Centre
 * Air Support Operations Centre
 * Airport Security and Operations Centre
 * Antarctic and Southern Ocean Coalition
 * Atlanta Symphony Orchestra Chorus
 * Australian Standard Offence Classification
 * ASP
 * (i) Active Server Pages
 * American Society of Primatologists
 * Ammunition Supply Point
 * Application Service Provider (cf internet service provider)
 * Astronomical Society of the Pacific
 * Association of Surfing Professionals
 * ASPI – (i) Australian Strategic Policy Institute
 * ASR
 * (i) Alkali-silica reaction
 * Anti Slip Regulation
 * ASRAAM – (a) Advanced Short-Range Air-to-Air Missile
 * ASSC – (i) Association for the Scientific Study of Consciousness
 * Ass Paym – Assistant Paymaster
 * AST – (i) Atlantic Standard Time (UTC−4 hours)
 * ASTIA – (a) Armed Services Technical Information Agency
 * ASTM – (i) American Society for Testing and Materials
 * ASTREA – (a) Aerial Support To Regional Enforcement Agencies (sheriff's air support unit)
 * ASUN – (p) Atlantic Sun Conference, now branded as the ASUN Conference (pronounced "A-sun")
 * ASUW – (p) AntiSUrface Warfare
 * ASVAB–Armed Services Vocational Aptitude Battery (taken by juniors in high school in the USA)
 * ASVEL – (a) Association Sportive Villeurbanne Éveil Lyonnais (Association Sportive is French for "Sporting Association"; the club was founded through the merger of AS Villeurbanne and Éveil Lyonnais)
 * ASW – (i) AntiSubmarine Warfare
 * ASWORG – (i) (U.S.) AntiSubmarine Warfare Operations Research Group
 * ASX
 * (p) Advanced Stream Redirector
 * Australian Securities Exchange

AT

 * aT – (s) Attotesla
 * At – (s) Astatine
 * AT – (i) Anti-Tank – (s) Ashmore and Cartier Islands (FIPS 10-4 territory code) – Austria (ISO 3166 digram) – (i) Advanced Technology (IBM Personal Computer/AT)
 * ATA – (i) Advanced Technology Attachment (IBM Personal Computer) – Afghan Transitional Authority – Allen Telescope Array – (s) Antarctica (ISO 3166 trigram)
 * ATAC – (a) Air Transportable Acoustic Communications
 * ATACMS – (p) Army TACtical Missile System
 * ATAPI – (a) Advanced Technology Attachment Packet Interface
 * ATAS – (a) Air-To-Air Stinger (missile)
 * ATAT – (a) Aiken Tactical Airsoft Team / Star Wars vehicle
 * ATB
 * (i) Active Time Battle
 * (s) British Antarctic Territory (ISO 3166 trigram; merged with AQ in 1979)
 * ATC –
 * (i) Air Traffic Control
 * Air Training Corps
 * U.S. Air Transport Command (1942–1948)
 * Athletic Trainer, Certified (www.nata.org)
 * ATCCIS – (i) Army Tactical Command and Control Information System
 * ATEBAWLS – (a) Association Towards Engineers Balling at Wii Lover's Sports
 * ATESS – (i) Aerospace and Telecommunications Engineering Support Squadron
 * ATF
 * (s) French Southern Territories (ISO 3166 trigram)
 * (i) (U.S.) Bureau of Alcohol, Tobacco, Firearms and Explosives (from its previous name, which did not include "Explosives")
 * ATG – (s) Antigua and Barbuda (ISO 3166 and FIFA trigram)
 * ATGM – (i) Anti-Tank Guided Missile
 * ATGW – (i) Anti-Tank Guided Weapon
 * ATI –
 * (i) Allied Telesyn International, Inc.
 * (a) Array Technologies Incorporated. (ATI Technologies)
 * Air Transport International - American cargo airline
 * Atisbo – a Local Government Area in Nigeria named for constituent communities (Ago-Are, Tede, Irawo, Sabe, Baasi, Ofiki and Owo)
 * ATK – (p) Attack
 * ATL – (p) Atlanta, Georgia, the largest city and capital of Georgia; taken from the IATA code for its airport
 * ATLAS –
 * (a) All-Terrain Lifter Army System
 * (p) Assessment Tool for LAnd Systems
 * ATM –
 * (i) Automated Teller Machine
 * Asynchronous Transfer Mode
 * At The Moment
 * ATN – (s) Dronning Maud Land (ISO 3166 trigram; merged with AQ in 1983)
 * ATO
 * (i) Air Tasking Order
 * Australian Taxation Office
 * ATP
 * (i) Adenosine TriPhosphate
 * Allied Tactical Publication
 * Ammunition Transfer Point
 * Association of Tennis Professionals (cf. ATP Tour, ATP Challenger Tour, ATP Champions Tour)
 * ATSD – (p) (U.S.) Assistant Secretary of Defense
 * ATSDR – (i) Agency for Toxic Substances and Disease Registry
 * AT&T – (i) American Telephone and Telegraph (U.S. company, also known as "Ma Bell")
 * ATV
 * (i) All-terrain vehicle
 * Associated Television – former UK TV company
 * ATWA – (a) Air, Trees, Water, Animals

AU

 * Au – (s) Gold (Latin Aurum)
 * AU –
 * (i) African Union (was OAU before 2000)
 * American University
 * (s) Astronomical Unit
 * Australia (ISO 3166 diagram)
 * Austria (FIPS 10-4 country code)
 * AUC –
 * (i) Ab Urbe Condita / Anno Urbis Conditae (Latin "from the founding of the city" / "in the year since the founding of the city") (of Rome)
 * Area Under the Curve (concentration time curve; medicine)
 * AUD – (s) Australian dollar (ISO 4217 currency code)
 * AUG – (a) Armee-Universal-Gewehr (German, Army Universal Rifle)
 * AUS – (s) Australia (ISO 3166 trigram)
 * AUSCANNZUKUS – (p) Australia, Canada, New Zealand, United Kingdom, United States (security designation)
 * Auslan – (p) Australian Sign Language
 * AUT – (s) Austria (ISO 3166 trigram)
 * AUTL – (i) Army Universal Task List

AV

 * av – (s) Avar language (ISO 639-1 code)
 * aV – (s) Attovolt
 * Av – (i) Aperture value (photographic mode)
 * AV
 * (s) Anguilla (FIPS 10-4 territory code)
 * (i) Audio-Visual
 * (s) Aviation
 * ava – (s) Avar language (ISO 639-2 code)
 * AVA – (i) American Viticultural Area
 * AVB – (i) Audio Video Bridging
 * AVCATT-A – (p) (U.S. Army's) Aviation Combed Arms Tactical Trainer-Aviation [Reconfigurable Manned Simulator]
 * AVDLR – (p) Aviation Depot Level Repair
 * ave – (s) Avestan language (ISO 639-2 code)
 * AVGP – (i) Armoured Vehicle, General Purpose
 * AVI – (i) Audio Video Interleave
 * AVIM – (p) Aviation Intermediate Maintenance
 * AVLB – (i) Armoured Vehicle Launched Body
 * AVM
 * (i) Air Vice-Marshal
 * (p) Arteriovenous malformation
 * AVO – (i) Apprehended Violence Order
 * AVP – (a) Arubaanse Volkspartij
 * AVP – (i) Association of Volleyball Professionals
 * AVRE – (i) Armoured Vehicle Royal Engineers
 * AVTB
 * (i) Armoured Vehicle Test Bed
 * (p) Aviation Test Bed
 * AVUM – (p) Aviation Unit Maintenance
 * AVUS – (a) Automobil-Verkehrs- und Übungsstraße (German, "Automobile Traffic and Training Road"; former auto racing track and current road in Berlin)
 * AVVO – (a) Acute Vaginal Venereal Outbreak

AW

 * aW – (s) Attowatt
 * AW – (s) Aruba (ISO 3166 digram)
 * AWA – (i) American Wrestling Association
 * AWACS – (a) Airborne Warning And Control System
 * AWC – (i) Air Warfare Centre
 * AWD – many, including All Wheel Drive; see entry
 * AWE – (i/a) Advanced Warfighting Experiment
 * AWG – (s) Aruban guilder (ISO 4217 currency code)
 * AWOL – (a) Absent Without Official Leave / Absent WithOut Leave (military jargon)
 * AWP – (p) Awaiting Parts (SM&R code)
 * AWSIM – (p) Air Warfare SIMulation
 * AWST – (a) Australian Western Standard Time
 * AWW – (i) Above-Water Warfare

AX

 * AX – (s) Åland (ISO 3166 digram)
 * AXP – (p) Ambulance eXchange Point

AY

 * ay – (s) Aymara language (ISO 639-1 code)
 * AY – (s) Antarctica (FIPS 10-4 territory code)
 * AYBABTU – (i) All Your Base Are Belong To Us
 * aym – (s) Aymara language (ISO 639-2 code)
 * AYU – (i) As Yet Unknown

AZ

 * az – (s) Azerbaijani language (ISO 639-1 code)
 * AZ
 * (s) Arizona (postal symbol)
 * Azerbaijan (ISO 3166 digram)
 * (i) Alkmaar Zaanstreek (Dutch football club)
 * AZAL – Azerbaijan Airlines
 * aze – (s) Azerbaijani language (ISO 639-2 code)
 * AZE – (s) Azerbaijan (ISO 3166 trigram)
 * AZN – (s) Azerbaijani manat (ISO 4217 currency code)
 * AZUR – (p) Actions en zone urbaine (French, Urban Operations)