intelligence activities concerned with identifying and counteracting the threat to security posed by hostile intelligence organizations or by individuals engaged in espionage or sabotage or subversion or terrorism
(computer science) the area of the screen in graphical user interfaces against which icons and windows appear
a person's social heritage: previous experience or training; "he is a lawyer with a sports background"
information that is essential to understanding a situation or problem; "the embassy filled him in on the background of the incident"
the part of a scene (or picture) that lies behind objects in the foreground; "he posed her against a background of rolling hills"
relatively unimportant or inconspicuous accompanying situation; "when the rain came he could hear the sound of thunder in the background"
extraneous signals that can be confused with the phenomenon to be observed or measured; "they got a bad connection and could hardly hear one another over the background signals"
understate the importance or quality of; "he played down his royal ancestry"