n. & v.
n. 1 a a piece of cloth, usu. oblong or square, attachable by one edge to a pole or rope and used as a country's emblem or as a standard, signal, etc. b a small toy, device, etc., resembling a flag. 2 Brit. an oblong strip of metal etc. that can be raised or lowered to indicate whether a taxi is for hire or occupied. 3 Naut. a flag carried by a flagship as an emblem of an admiral's rank afloat.
v. (flagged, flagging) 1 intr. a grow tired; lose vigour; lag (his energy flagged after the first lap). b hang down; droop; become limp. 2 tr. a place a flag on or over. b mark out with or as if with a flag or flags. 3 tr. (often foll. by that) a inform (a person) by flag-signals. b communicate (information) by flagging. black flag 1 a pirate's ensign. 2 hist. a flag hoisted outside a prison to announce an execution. flag-boat a boat serving as a mark in sailing-matches. flag-captain the captain of a flagship. flag-day Brit. a day on which money is raised for a charity by the sale of small paper flags etc. in the street. Flag Day US 14 June, the anniversary of the adoption of the Stars and Stripes in 1777. flag down signal to (a vehicle or driver) to stop. flag-lieutenant Naut. an admiral's ADC. flag-list Naut. a roll of flag-officers. flag of convenience a foreign flag under which a ship is registered, usu. to avoid financial charges etc. flag-officer Naut. an admiral, vice admiral, or rear admiral, or the commodore of a yacht-club. flag of truce a white flag indicating a desire for a truce. flag-pole = FLAGSTAFF. flag-rank Naut. the rank attained by flag-officers. flag-station a station at which trains stop only if signalled. flag-wagging sl. 1 signalling with hand-held flags. 2 = flag-waving. flag-waver a populist agitator; a chauvinist. flag-waving populist agitation, chauvinism. keep the flag flying continue the fight. put the flag out celebrate victory, success, etc. show the flag 1 make an official visit to a foreign port etc. 2 ensure that notice is taken of one's country, oneself, etc.; make a patriotic display. flagger n.
[ 16th c.: perh. f. obs. flag drooping ]