flag
noun
°A piece of cloth, often decorated with an emblem, used as a visual signal or symbol.
°(nautical) A flag flown by a ship to show the presence on board of the admiral; the admiral himself, or his flagship.
verb
°To mark with a flag, especially to indicate the importance of something.
°(often with down) To signal to, especially to stop a passing vehicle etc.
synonyms: boolean, switch