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.