Other forms: flags, flagged, flagging
A flag is a piece of cloth with a country's colours on a pole. Raise the flag, the national flag, fly the flag.
Vexillology is the study of them, and the best ones follow a few rules — simple enough for a child to draw from memory, meaningful, and no lettering. Flying a flag at half mast marks mourning. As a verb, to flag means to mark for attention, and also to lose energy: flagging interest. Note red flag; and flagship, from the ship carrying the admiral.
1nounflagA piece of cloth with a country's colours on a pole.
“The national flag was flying above the town hall.”
2verbmarkTo mark for attention, or to lose energy.
“The teacher flagged a few spelling mistakes in red.”
Too few real examples of this word to estimate which sense is commonest.
flag is a cloth emblem, or a marking.
Middle English flagge is of uncertain origin, possibly imitative of something flapping. The verb meaning to droop may be a separate word entirely.
Middle English
flag
English, today
flag
Built from
From Middle English flag, flagge (“flag”), further etymology unknown. Perhaps from or related to early Middle English flage name for a baby's garment and Old English flagg, flacg (“cataplasm, poultice, plaster”). Or, perhaps ultimately imitative of the sound, or otherwise drawn from Proto-Germanic flaką (“something flat”), from Proto-Indo-European pleh₂- (“flat, broad, plain”), referring to the shape. Germanic cognates include Saterland Frisian Flaage (“flag”), West Frisian flagge (“flag”), Dutch vlag (“flag”), German Flagge (“flag”), Swedish flagga (“flag”), Danish flag (“flag, ship's flag”). Compare also Middle English flacken (“to flutter, palpitate”), Swedish - dialectal flage (“to flutter in the wind”), Old Norse flögra (“to flap about”). Akin to Old High German flogarōn (“to flutter”), Old High German flogezen (“to flutter, flicker”), Middle English flakeren (“to move quickly to and fro”), Old English flacor (“fluttering, flying”). More at flack, flacker.
Etymology from Wiktionary, CC BY-SA