noun A piece of cloth, often decorated with an emblem, used as a visual signal or symbol.
noun The design that could be placed on a flag, typically a rectangular graphic that is used to represent an entity (like a country, organisation or group of people) or an idea.
The flag of France has three vertical stripes.
noun A flag flown by a ship to show the presence on board of the admiral; the admiral himself, or his flagship.
noun A signal flag.
noun The use of a flag, especially to indicate the start of a race or other event.
noun A variable or memory location that stores a Boolean true-or-false, yes-or-no value, typically either recording the fact that a certain event has occurred or requesting that a certain optional action take place.
noun In a command line interface, a command parameter requesting optional behavior or otherwise modifying the action of the command being invoked.
noun A mechanical indicator that pops up to draw the pilot's attention to a problem or malfunction.