red flags

Noun

red flag (plural red flags)

1. Used other than figuratively or idiomatically: see red, flag.
2. (figuratively) A cue, warning, or alert; a sign or signal that something is wrong.
   • Improper formatting is a red flag that you should look for other problems with the data.

   Antonyms:

   green flag

   1. (figuratively) A flag used as a signal that the race must be stopped immediately (and possibly restarted).
      • Typically, a red flag is used when it rains or when the safety of the clean-up crews is in danger because there is too much debris or oil on the track.2005, James A. Vlasich, Horsehide, Pigskin, Oval Tracks and Apple Pie, →ISBN, page 177
   2. (UK, figuratively, historical) A flag formerly used by a railway guard to warn the driver not to start the train.
3. A red or predominantly red flag symbolizing a left-wing ideological movement, such as socialism, communism or the labour movement.
   • Some chanted: "Pride, pride, national pride" and "Poland should be national not red or rainbow-coloured", in a reference to the red flag of the Soviet Union and the symbol of gay pride.2018 November 11, “Polish government officials march with far-right groups to mark century of independence”, in The Daily Telegraph, archived from the original on 07 Mar 2023
4. (US, figuratively) Something that will enrage a particular person; a red rag.

See all 9 meanings of red flag