red flag

== English == === Pronunciation === === Noun === red flag (plural red flags) (literally) A flag that is red, especially associated with leftist revolutionary ideologies. (motor racing) A flag used as a signal that the race must be stopped immediately (and possibly restarted). (informal, figurative) A cue, warning, or alert; a sign or signal that something is wrong. Antonym: green flag (idiomatic, US) Something that will enrage a particular person; a red rag. (rail transport, UK) A flag formerly used by a railway guard to warn the driver not to start the train. ==== Coordinate terms ==== ==== Derived terms ==== ==== Translations ==== === See also === Hongqi === Further reading === “red flag”, in Merriam-Webster.com Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present. “red flag”, in Dictionary.com Unabridged, Dictionary.com, LLC, 1995–present. “red flag”, in Collins English Dictionary, 2011–present. “red flag, n.”, in OED Online ⁠, Oxford: Oxford University Press, launched 2000. “red-flag, v.”, in OED Online ⁠, Oxford: Oxford University Press, launched 2000.