Indicator

Indicator may refer to:

Biology

 * Environmental indicator of environmental health (pressures, conditions and responses)
 * Ecological indicator of ecosystem health (ecological processes)
 * Health indicator, which is used to describe the health of a population
 * Honeyguides, also known as "indicator birds", a family of Old World tropical birds
 * Indicator (genus), a genus of birds in the honeyguide family
 * Indicator species, a species that defines a characteristic of an environment
 * Indicator bacteria, bacteria used to detect and estimate the level of fecal contamination of water
 * Indicator organism, organisms used to measure such things as potential fecal contamination of environmental samples
 * Indicator plant, a plant that acts as a measure of environmental conditions
 * Indicator value, one of two terms in ecology referring to the classification of organisms
 * Iodine–starch test, a method to test for the presence of starch or iodine.

Chemistry

 * Complexometric indicator, a chemical detector for metal ions in complexometric titrations.
 * Humidity indicator card, a card impregnated with chemicals that change colour when a particular humidity is exceeded.
 * pH indicator, a chemical detector for protons in acid-base titrations.
 * Redox indicator, a chemical detector for redox titrations.
 * Zeta potential, a property of interfaces in fluids for Zeta potential titration.

Economics

 * Economic indicator
 * Macroeconomic indicators, economic indicators provided by agencies and bureaus of various government statistical organizations and sometimes by private organizations
 * Performance indicator
 * Technical indicator, a tool used in the technical analysis of financial securities

Mathematics, engineering, and industry

 * Indicator (distance amplifying instrument), any of various instruments used to accurately measure small distances, and amplify them to make them more obvious
 * Indicator (metadata), a Boolean value that may contain only the values true or false and includes the meaning of these values
 * Indicator (statistics), a concept in statistics, research design and social sciences
 * Indicator diagram, a graph of pressure against stroke within a piston engine
 * Indicator function of a subset of the domain, a concept in mathematics
 * Indicator net, nets anchored at various depths to the sea bed around Allied naval bases during World War II intended to entangle U-boat traffic of the enemy
 * Indicator of compromise, an artifact observed in computer forensics that indicates an intrusion

Other uses

 * Indicator (Deine Lakaien album), 2010
 * Indicator (Onward to Olympas album), 2012
 * Indicator Island, in the Argentine Islands of Antarctica
 * The Indicator (1819–1821), a weekly literary journal edited by Leigh Hunt
 * The Indicator, a daily podcast produced by Planet Money
 * A synonym for the turn signal of an automobile