yellow alert

  1. (in military or civilian defense) the first alert given when enemy aircraft are discovered approaching a military installation, city, coastline, etc.: Compare blue alert, red alert, white alert.

  2. the signal or alarm sounded for this alert.

  1. any primary stage of alert, as when toxic chemicals have escaped in a particular area and a potential hazard exists.

Origin of yellow alert

First recorded in 1965–70

Words Nearby yellow alert Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023