verb (used with object), red-flagged, red-flag·ging.

to mark or draw attention to for a particular purpose: The department has red-flagged the most urgent repair work to be done.
to provoke the attention of; alert; arouse: The animal's refusal to eat red-flagged the keeper that something was wrong.


of or relating to a red flag.
intended or serving to emphasize, warn, incite, or provoke.

Origin of red-flag

First recorded in 1880–85

red flag


the symbol or banner of a left-wing revolutionary party.
a danger signal.
something that provokes an angry or hostile reaction: The talk about raising taxes was a red flag to many voters.
Also called powder flag. Nautical. a red burgee, designating in the International Code of Signals the letter “B,” flown by itself to show that a vessel is carrying, loading, or discharging explosives or highly inflammable material.
(initial capital letters) a war game the U.S. Air Force holds several times each year at Nellis Air Force Base, Nevada, to train personnel in air combat.

Origin of red flag

First recorded in 1770–80 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for red-flag

Contemporary Examples of red-flag

  • When it gets parched in Los Angeles the weather service issues a “red-flag” warning to indicate that the risk of fire is high.

    The Daily Beast logo
    NBC Universal Sees Red

    Kim Masters

    July 19, 2009

Historical Examples of red-flag

  • A lot of them fur-faced boys that hurl the merry bombs are goin' to pull off a red-flag sashay up the Avenoo.

    The Wrong Twin

    Harry Leon Wilson

British Dictionary definitions for red-flag

red flag


a symbol of socialism, communism, or revolution
a warning of danger or a signal to stop

Red Flag


the Red Flag a socialist song, written by James Connell (1852–1929), Irish political activist, in 1889
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012