background n. 1.Ground in the rear or behind, or in the distance, as opposed to the foreground, or the ground in front.
2.(Paint.) The space which is behind and subordinate to a portrait or group of figures. Note: The distance in a picture is usually divided into foreground, middle distance, and background.
3.Anything behind, serving as a foil; as, the statue had a background of red hangings.
4.A place in obscurity or retirement, or out of sight. "I fancy there was a background of grinding and waiting before Miss Torry could produce this highly finished... performance." "A husband somewhere in the background."
5.The set of conditions within which an action takes place, including the social and physical conditions as well as the psychological states of the participants; as, within the background of the massive budget deficits of the 1980's, new spending programs had little chance of passage by the congress.
6.The set of conditions that precede and affect an action, such as the social and historical precedents for the event, as well as the general background (5); as, against the background of their expulsion by the Serbs, the desire of Kosovars for vengeance is understandable though regrettable.
7.(Science) The signals that may be detected by a measurement which are not due to the phenomenon being studied, and tend to make the measurement uncertain to a greater or lesser degree. Specifically: (Physics) Electronic noise present in a system using electronic measuring instrument or in a telecommunications system, which may hide and which must be differentiated from the desired signal; also called background noise or noise.
8.(Journalism) An agreement between a journalist and an interviewee that the name of the interviewee will not be quoted in any publication, although the substance of the remarks may be reported; often used in the phrase "on background". Compare deep background.
To place in the background, to make of little consequence.
To keep in the background, to remain unobtrusive, inconspicuous or out of sight; of people.
deep background, (Journalism) the status of an interview which must not be quoted in a publication, even without attribution. Compare background (8). 
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