N (disambiguation)

N is the fourteenth letter of the English alphabet.

N or n may also refer to:

Mathematics

 * $$\mathbb{N}$$ or N, the set of natural numbers
 * N, the field norm
 * N for nullae, a rare Roman numeral for zero
 * n, the size of a statistical sample

Science

 * ATC code N Nervous system, a section of the Anatomical Therapeutic Chemical Classification System
 * Haplogroup N (mtDNA), a human mitochondrial DNA haplogroup
 * Haplogroup N (Y-DNA), a human Y-chromosome DNA haplogroup
 * N band, an atmospheric transmission window in the mid-infrared centred on 10 micrometres
 * N ray, a hypothesized form of radiation, found to be illusory
 * N., abbreviation of the Latin word nervus meaning nerve, used in anatomy, e.g. N. vagus

Quantities and units

 * N for Newton (unit), the SI derived unit of force
 * N or $$F_n$$, a normal force in mechanics
 * Nitrogen, symbol N, a chemical element
 * N or Asn, the symbol for the common natural amino acid asparagine
 * N, the Normality (chemistry) or chemical concentration of a solution
 * N, the neutron number, the number of neutrons in a nuclide
 * N, in Brillouin zone, the center of a face of a body-centered cubic lattice
 * N, the physical quantity "rotation" in the International System of Quantities
 * n, for nano-, prefix in the SI system of units denoting a factor of 10−9
 * n, the optical refractive index of a material
 * n, the principal quantum number, the first of a set of quantum numbers of an atomic orbital
 * n, an electron density, the measure of the probability of an electron being present at a specific location
 * n, an amount of substance in chemical physics
 * n, the coordination number of a substance
 * n-, a lowercase prefix in chemistry denoting the straight-chain form of an open-chain compound in contrast to its branched isomer
 * N-, an uppercase prefix in chemistry denoting that the substituent is bonded to the nitrogen, as in amines

Transport

 * N (New York City Subway service), a service of the New York City Subway
 * N Judah, a Muni Metro line in San Francisco, California
 * N (Los Angeles Railway), a line operated by the Los Angeles Railway from 1920 to 1950
 * Tokyo Metro Namboku Line, a subway service operated by the Tokyo Metro, labeled Logo of Tokyo Metro Namboku Line.svg
 * Nagahori Tsurumi-ryokuchi Line, a subway service operated by the Osaka Metro, labeled Osaka Metro Nagahori Tsurumi-ryokuchi line symbol.svg
 * Transilien Line N, a line of the Paris transport network
 * JRW oka-N.svg, the official West Japan Railway Company service symbol for the Akō Line.

Engineering

 * N, in geotechnical engineering, the result of a standard penetration test
 * N, in electrical systems, the connection to neutral
 * N, an ITU prefix allocated to the United States for radio and television stations
 * n (Poland), a digital TV platform
 * N battery or N cell, a standard size of dry cell battery
 * N connector, a threaded RF connector for joining coaxial cables

Entertainment

 * N. (novella), a 2008 short story by Stephen King
 * Near (Death Note) (alias N), a character in the manga series Death Note
 * N (video game), a 2005 computer game
 * N (Pokémon), the leader and king of crime syndicate Team Plasma in the Pokémon franchise
 * The N, a block on the Noggin TV channel
 * N, the production code for the 1965 Doctor Who serial The Web Planet
 * "N" Is for Noose, the fourteenth novel in Sue Grafton's "Alphabet mystery" series, published in 1998

Music

 * N (singer), stage name of Cha Hak-yeon, leader of the South Korean boy band VIXX
 * N, an alias of Drew Mulholland, who recorded more often as Mount Vernon Arts Lab
 * N (album), a 2008 album by Norther
 * "N", a song by BanYa for the "Pump It Up: The Perfect Collection" music video game
 * "n", a song by iamamiwhoami

Language

 * , the International Phonetic Alphabet symbol for a voiced alveolar nasal sound
 * ,, , , , , , , , , symbols representing other nasal consonants in the International Phonetic Alphabet
 * N (kana), a Japanese kana
 * Noun, a part of speech

Other uses

 * Hyundai N, high performance brand of Hyundai Motor Company
 * N, North, one of the cardinal directions of the compass
 * N postcode area, the part of the London post town covering part of North London, England
 * ₦, the symbol for the Nigerian naira currency
 * N, the code used to denote vehicle registration plates of Norway
 * N-class ferry, a class of small RORO ferry
 * N scale or N gauge, a popular model railway size
 * N, the identifier for the knight (chess) in algebraic notation
 * November, the military time zone code for UTC−01:00
 * Nachrichten-Abteilung, naval intelligence department of Imperial German