1. 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)
