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 1a

(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 of indicator

• needle
• index

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

Lastly, mortgage rates and where they have been headed can be an indicator. —Becca Stanek, TheWeek, 27 Apr. 2026

Still, your age can offer a few indicators about what your skin needs, which, for many people in their late 30s and beyond, is moisture and a light touch. —Annie Blay-Tettey, Allure, 27 Apr. 2026

The game was also the latest indicator that Mayer is starting to figure things out at the plate. —Mac Cerullo, Boston Herald, 26 Apr. 2026

And in most cases, bright red ground beef is one indicator of freshness. —Karla Walsh, Better Homes & Gardens, 26 Apr. 2026

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