indicator

noun

in·​di·​ca·​tor ˈin-də-ˌkā-tər 

1

: one that indicates: such as

a

: an index hand (as on a dial) : pointer

b(1)

: gauge sense 2b, dial sense 4a

(2)

: an instrument for automatically making a diagram that indicates the pressure in and volume of the working fluid of an engine throughout the cycle

2

: any of a group of statistical values (such as level of employment) that taken together give an indication of the health of the economy

3

a

: a substance (such as litmus) used to show visually (as by change of color) the condition of a solution with respect to the presence of a particular material (such as a free acid or alkali)

b

: tracer sense 4b

4

: an organism or ecological community so strictly associated with particular environmental conditions that its presence is indicative of the existence of these conditions

indicatory

in-ˈdi-kə-ˌtȯr-ē 

adjective

Synonyms

• needle
• index
• gauge

Examples of indicator in a Sentence

Economic indicators suggest that prices will go up.

a control panel with various indicator lights

Recent Examples on the Web

Note that the relative strength indicator has declined from late 2024 to the present – heading in the opposite direction of the price. —John Navin, Forbes.com, 6 Sep. 2025

If Verdun is any indicator, these estimates are conservative at best. —Michael Jerome Plunkett september 5, Literary Hub, 5 Sep. 2025

Lenovo's tear through a succession of Legion Go products is a mighty indicator that PC gaming handhelds aren't just a fad. —Zackery Cuevas, PC Magazine, 5 Sep. 2025

And patients without visible signs of starvation showed severe electrolyte imbalances and significant anemia in their lab results — clear indicators of malnutrition, Ali said. —Brendan Rascius, Fort Worth Star-Telegram, 5 Sep. 2025

Word History

First Known Use

1666, in the meaning defined at sense 1

Phrases Containing indicator

• plan position indicator

Rhymes for indicator

• activator
• actuator
• agitator
• alligator
• allocator
• alternator
• animator
• annotator
• applicator
• arbitrator
• aspirator
• aviator

Kids Definition

indicator

noun

in·​di·​ca·​tor ˈin-də-ˌkāt-ər 

1

: one that indicates: as

a

: a pointer on a dial or scale

b

: gauge entry 1 sense 2a

2

: a substance used to show visually (as by change of color) the presence of acid or base in a solution

Medical Definition

indicator

noun

in·​di·​ca·​tor ˈin-də-ˌkāt-ər 

: a substance (as a dye) used to show visually (as by a change in color) the condition of a solution with respect to the presence of a particular material (as a free acid or alkali)

litmus and phenolphthalein are acid-base indicators