noun

indicator

IN-di-kay-ter/ˈɪndɪkeɪtər/

Something that reveals a condition through an observable sign.

The fuel indicator points near empty, revealing how little fuel remains.

A close-up of a car's fuel indicator: a clearly visible needle points toward the nearly empty end of a graduated gauge, with a small fuel-pump pictogram identifying what it indicates.

Etymology

inLatinin, upon

+dicatLatinproclaim

+orLatinone or thing that acts

The prefix and “proclaim” combined in a verb meaning “point out, show.” The agent ending makes an indicator something that does this showing, such as a gauge revealing a level or pressure.

In context

Smoke & Stardust3:26

Stratus clouds are pretty much always an indicator for gloomy weather

How to Read the Sky: Predict the Weather Just by Looking Up!!

More examples

Rising home sales are one indicator of a stronger economy.
The battery indicator shows how much charge remains.
This chemical indicator turns pink when the solution becomes basic.

Forms

indicator · indicators

indicate verb — To show or point something out.

Similar words

sign: A broader term for something that suggests a condition.
gauge: Usually a device or measure used to assess something.
signal: Often a noticeable change or event that conveys information.