from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A warning signal.
  • noun Something that demands attention or provokes an irritated reaction.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun idiomatic A cue, warning, or alert; a sign or signal that something is wrong.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun the emblem of socialist revolution
  • noun something that irritates or demands immediate action
  • noun a flag that serves as a warning signal


Sorry, no etymologies found.


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  • The red flag flies at dawn.

    Seriously, I have one (actually two) of these on my work desk. They are a recently adopted office-wide signal (when placed atop the cubicle cabinet for all to see) that the person is on the phone or seriously busy and desires quiet.

    January 23, 2008

  • Why do I have a red flag on my screen whenever I'm on the home page these days? Was it decided democratically in my absence? Can't believe it's Google.

    March 18, 2009