indicator

IPA/ˈɪndɪkeɪtə(r)/
KK[ˈɪndəkˌetɚ]IPA/ˈɪndɪkeɪtər/

indicator — noun

  • indicatorsingular
  • indicatorsplural

1. something you can observe or measure that tells you about the present state of t

1.nounB2
Definition

something you can observe or measure that tells you about the present state of things or what may happen soon.

Example

Chidi's frequent coughing was the first indicator that he was coming down with a cold.

indicator + that-clause for showing evidence

Falling test scores across the school are often an indicator of problems in the classroom.

Common collocations
  • reliable indicator
  • key indicator
  • important indicator
  • clear indicator
  • early indicator
  • indicator of
Synonyms
  • sign

    more general, less formal; can be any visible clue

  • signal

    suggests a deliberate or direct warning about something

  • symptom

    used specifically for medical or problem-related conditions; something bad

Grammar Patterns

indicator + of + noun phrase

indicator + that-clause

Usage Note

Subject is often a measurable or observable fact (test scores, prices, temperature). The preposition 'of' connects the indicator to the situation it reveals.

Common Mistakes

The dark clouds are a good indication that rain is coming.
The dark clouds are a good indicator that rain is coming.
'indication' refers to the act of showing; 'indicator' is the thing that shows it.

2. a flashing light on a car or motorcycle that the driver uses to tell other road

2.nounA2
Definition

a flashing light on a car or motorcycle that the driver uses to tell other road users they plan to go left or right.

Example

Mateo forgot to use his indicator before turning left at the junction.

collocation: use your indicator

The car in front had a broken indicator on the passenger side.

broken indicator — describing a faulty part

Common collocations
  • use your indicator
  • check your indicator
  • indicator light
  • left indicator
  • right indicator
  • indicator flashing
Synonyms
  • turn signal

    standard American term

  • blinker

    informal term used in both American and British English

Grammar Patterns

possessive + indicator

use + indicator

Usage Note

Standard term in British English. In American English, 'turn signal' or 'blinker' is more common. 'Blinker' is informal in both varieties.

Common Mistakes

I forgot to turn on my direction light.
I forgot to use my indicator.
'direction light' is not a standard term; 'indicator' (UK) or 'turn signal' (US) is correct.

3. a part of a machine or control panel that displays a reading such as speed, temp

3.nounB1
Definition

a part of a machine or control panel that displays a reading such as speed, temperature, or the amount of fuel remaining.

Example

The speed indicator showed we were driving at one hundred and ten kilometres per hour.

collocation: speed / fuel / temperature indicator

Niran checked the fuel indicator before setting off on the long journey.

Common collocations
  • speed indicator
  • fuel indicator
  • temperature indicator
  • pressure indicator
  • indicator shows
  • indicator reads
Synonyms
  • gauge

    more specific; often refers to a round dial with a needle

  • dial

    focuses on the circular face of a measuring device

  • meter

    device that measures and records usage, e.g. electricity or water

Grammar Patterns

noun + indicator

indicator + shows/reads

Usage Note

Often combined with a noun naming what is measured (speed indicator, fuel indicator, temperature indicator). The verb 'read' or 'show' is typically used with this sense.

4. in chemistry, a material that shifts colour when mixed with a specific chemical,

4.nounB2
Definition

in chemistry, a material that shifts colour when mixed with a specific chemical, allowing scientists to tell whether a solution is acidic or basic.

Example

Litmus paper is a common indicator that turns red in acid and blue in alkali.

litmus paper as indicator — acid/base test

A chemist added indicator to the beaker and watched for a colour change.

Common collocations
  • chemical indicator
  • add an indicator
  • universal indicator
  • indicator solution
  • colour change of indicator
Synonyms
  • litmus

    a specific type of indicator made from lichen; often used as a general term for any test

  • reagent

    broader term for any substance used in a chemical reaction to detect another substance

Grammar Patterns

indicator + noun

add + indicator

Usage Note

Domain-specific to chemistry. The most well-known example is litmus paper. Rarely used outside scientific or educational contexts.

5. a piece of statistical information that helps people understand the general cond

5.nounB2
Definition

a piece of statistical information that helps people understand the general condition of a country's economy or the direction in which it is moving.

Example

The unemployment rate is an important indicator of a country's economic health.

collocation: economic indicator

The government publishes several key economic indicators at the end of each quarter.

key economic indicator + passive (publishes)

Common collocations
  • economic indicator
  • key indicator
  • leading indicator
  • financial indicator
  • inflation indicator
Synonyms
  • metric

    more general term for any measured value; used in business and data contexts

  • index

    a composite measure combining multiple data points into one number

  • benchmark

    a standard against which performance is measured

Grammar Patterns

economic + indicator

indicator + of

Usage Note

Commonly used in the plural ('indicators') when referring to a set of statistics. Typically modified by 'economic', 'key', 'leading', or 'financial'.

Common Mistakes

The GDP is a good indication of how the economy is doing.
GDP is a good indicator of how the economy is doing.
'indication' means a vague sign; 'indicator' is the specific measure itself.

Word family

Synonym discussion

Sense: noun/1

All four words refer to something that reveals information, but they differ in scope and connotation. 'Sign' is the broadest and most neutral term — anything visible that points to something else (dark clouds are a sign of rain). 'Signal' suggests a deliberate or direct communication, often a warning or instruction (a red light is a signal to stop). 'Clue' is used in problem-solving or detective contexts, where information helps solve a puzzle or mystery. 'Symptom' is restricted to medical or problem-related situations and usually carries a negative connotation (a cough is a symptom of a cold). 'Indicator' is the most formal and analytical of the four, often used for data-driven or measurable evidence (test scores as an indicator of school quality). For everyday situations, 'sign' sounds most natural; for formal reports or data analysis, 'indicator' is preferred.

sign ↗signal ↗clue ↗symptom ↗

Common collocations

Nouns

  • indicator light
  • indicator species

Adverbs

Phrases

  • act as an indicator
  • serve as an indicator
  • use something as an indicator

Prepositions

Etymology

LatinFrenchEnglish

Comes from Latin 'indicātor', meaning 'one who points out'. The root is the verb 'indicāre' (to point out, show), formed from 'in-' (towards) and 'dīcere' (to say, proclaim). The word entered English in the late 1600s, first used for people who pointed things out, then extended to devices and signs by the 1800s.