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yellow alert

American  

noun

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

  2. the signal or alarm sounded for this alert.

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

Etymology

Origin of yellow alert

First recorded in 1965–70

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

A yellow alert for snow and ice is in place for Counties Donegal, Cavan, Monaghan, Louth and Connacht.

From BBC • Jan. 5, 2026

A yellow alert for County Donegal lasts from 20:00 local time on Friday until 11:00 on Saturday.

From BBC • Jan. 3, 2026

North East England, North West England, Yorkshire and Humber and south-west England have a yellow alert for the same period.

From BBC • Aug. 11, 2025

But a yellow alert, issued by Caledonian MacBrayne on Sunday, said it may be subject to delay or cancellation due to high winds.

From BBC • Jan. 12, 2025

Until further notice, we must proceed under a yellow alert during daylight hours and a red alert at night.

From The Test Colony by Marks, Winston K.

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.