Princeton's WordNet

1. index, index number, indicant, indicator(noun)

   a number or ratio (a value on a scale of measurement) derived from a series of observed facts; can reveal relative changes as a function of time

2. indicator(noun)

   a signal for attracting attention

3. indicator(noun)

   a device for showing the operating condition of some system

4. indicator(noun)

   (chemistry) a substance that changes color to indicate the presence of some ion or substance; can be used to indicate the completion of a chemical reaction or (in medicine) to test for a particular reaction

Kernerman English Learner's Dictionary

1. indicator(noun)ˈɪn dɪˌkeɪ tər

   sth that shows the state or condition of sth

   high blood pressure as an indicator of diabetes; economic indicators

2. indicatorˈɪn dɪˌkeɪ tər

   a needle that points to a number on a piece of equipment

   The indicator was on "empty."

3. indicatorˈɪn dɪˌkeɪ tər

   turn signal

   Use your indicators.

Wiktionary

1. indicator(Noun)

   A pointer or index that indicates something.

2. indicator(Noun)

   A meter or gauge.

3. indicator(Noun)

   The needle or dial on such a meter.

4. indicator(Noun)

   Any of many substances, such as litmus, used to indicate the concentration of a substance, or the degree of a reaction.

5. indicator(Noun)

   A plant or animal whose presence is indicative of some specific environment.

6. indicator(Noun)

   A measure, such as unemployment rate, which can be used to predict economic trends.

7. indicator(Noun)

   A trafficator.

Origin: From indicator, from indico; see indicate.

Webster Dictionary

1. Indicator(noun)

   one who, or that which, shows or points out; as, a fare indicator in a street car

2. Indicator(noun)

   a pressure gauge; a water gauge, as for a steam boiler; an apparatus or instrument for showing the working of a machine or moving part

3. Indicator(noun)

   an instrument which draws a diagram showing the varying pressure in the cylinder of an engine or pump at every point of the stroke. It consists of a small cylinder communicating with the engine cylinder and fitted with a piston which the varying pressure drives upward more or less against the resistance of a spring. A lever imparts motion to a pencil which traces the diagram on a card wrapped around a vertical drum which is turned back and forth by a string connected with the piston rod of the engine. See Indicator card (below)

4. Indicator(noun)

   a telltale connected with a hoisting machine, to show, at the surface, the position of the cage in the shaft of a mine, etc

5. Indicator(noun)

   the part of an instrument by which an effect is indicated, as an index or pointer

6. Indicator(noun)

   any bird of the genus Indicator and allied genera. See Honey guide, under Honey

7. Indicator(noun)

   that which indicates the condition of acidity, alkalinity, or the deficiency, excess, or sufficiency of a standard reagent, by causing an appearance, disappearance, or change of color, as in titration or volumetric analysis

The Standard Electrical Dictionary

1. Indicator

   (a) An apparatus for indicating the condition of a distant element, such as the water level in a reservoir, the temperature of a drying room or cold storage room or any other datum. They are of the most varied constructions. (b) The receiving instrument in a telegraph system is sometimes thus termed.

Dictionary of Military and Associated Terms

1. indicator

   In intelligence usage, an item of information which reflects the intention or capability of an adversary to adopt or reject a course of action.

• aanwyserAfrikaans
• مُؤَشِّر، مِقْياسArabic
• показателBulgarian
• indicadorPortuguese (BR)
• ukazatelCzech
• der AnzeigerGerman
• måler; indikatorDanish
• indicador; intermitente (coche)Spanish
• näiturEstonian
• نشانگرFarsi
• ilmaisinFinnish
• aiguilleFrench
• מַחווָןHebrew
• सूचकHindi
• pokazivač, indikatorCroatian
• jelzőkészülékHungarian
• penunjukIndonesian
• vísir; mælirIcelandic
• indicatoreItalian
• 表示器Japanese
• 지시, 표시Korean
• indikatorius, rodyklėLithuanian
• indikators; rādītājsLatvian
• penunjukMalay
• wijzer, meterDutch
• viser, nål, indikatorNorwegian
• wskaźnikPolish
• نشانگرPersian
• ښوودونكيPashto
• indicadorPortuguese
• indicatorRomanian
• стрелка; указательRussian
• ukazovateľSlovak
• kazalecSlovenian
• indikatorSerbian
• visare, mätareSwedish
• ตัวบอก; เครื่องบอกThai
• ibreTurkish
• 指示器Chinese (Trad.)
• індикатор; покажчикUkrainian
• نشاندہی کرنے والاUrdu
• dụng cụ chỉ thịVietnamese
• 指示器Chinese (Simp.)