flag

v. decorate with flags; signal, warn; lose energy or momentum; become weak

n. banner, pennant; paving stone; any of a number of plants with long slender leaves (such as the iris, blue flag, etc.); tufts of feathers on the legs of birds; special symbol used to mark unusual data (Computers)

A flag is a piece of woven cloth, often flown from a pole or mast, generally used symbolically for signalling or identification. The term flag is also used to refer to the graphic design employed by a flag, or to its depiction in another medium. The first flags were used to assist military coordination on battlefields and flags have evolved into a general tool for rudimentary signalling and identification, This was especially used in environments where communication is similarly challenging (such as the maritime environment where semaphore is used). National flags are potent patriotic symbols with varied wide-ranging interpretations, often including strong military associations due to their original and ongoing military uses. Flags are used in messaging, advertising, or for other decorative purposes. The study of flags is known as vexillology, from the Latin vexillum meaning flag or banner.
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Flag may mean:Flag, a colored cloth with a specified meaningFlag (computing), a code with an assigned meaningFlag (lighting), an object used to block lightFlag (linear algebra), an increasing sequence of subspaces of a vector space.Flag (geometry), part of a polygon, polyhedron or higher polytopeFlagstone, a large flat stone used for paving, fencing, or roofingBlue Flag or Flag, a popular wild or cultivated flower of the family Iridaceae.Purple Flag, an Australian flower of the family Iridaceae.Fiber-Optic Link Around the Globe, an undersea fiber optic cable Flag (Yello album), a 1988 album by the band YelloFoundation for Law And Government (FLAG), a fictitious law-enforcement agency in the 1980s television show Knight Rider.FLAG-tag, a unique epitope added to proteins in biochemistry.Flags (sport), a beach sport played in surf lifesaver trainingFLAG (anime), a series by Kazuo TeradaFabbrica Ligure Automobili Genova (FLAG), an Italian automobile manufacturer
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In data transmission or processing, an indicator, such as a signal, symbol, character, or digit, used for identification. Note: A flag may be a byte, word, mark, group mark, or letter that signals the occurrence of some condition or event, such as the end of a word, block, or message.

1. <programming> A variable or quantity that can take on one of two values; a bit, particularly one that is used to indicate one of two outcomes or is used to control which of two things is to be done. "This flag controls whether to clear the screen before printing the message." "The program status word contains several flag bits." See also hidden flag, mode bit.
2. command line option.
[Jargon File]
(1998-05-02)

A chart pattern reflecting price fluctuations within a narrow range, generating a rectangular area on a chart both prior to and after sharp rises or declines.