warning light

English

Noun

warning light (plural warning lights)

1. A light on a dashboard or control panel that lights up when something undesirable has happened, or is about to happen; or if placed on a tall structure, to warn aircraft of its presence.

   Synonym: idiot light

   • 1958 June, “Main-Line Diesel-Electric Locomotives for the Eastern Region”, in Railway Magazine, page 395:

     Additional warning lights are provided to indicate diesel engine shut-down, traction motor blower failure or high engine cooling water temperature. On the assistant's side of the cab, another light shows should the train heating boiler shut down.

References

• “warning light”, in Collins English Dictionary, 2011–present.