background

[ˈbækˌɡraʊnd]
n
the part of a scene or view furthest from the viewer
an inconspicuous or unobtrusive position (esp in the phrase in the background).(as modifier)
the plane or ground in a picture upon which all other planes or forms appear superimposed.the parts of a picture that appear most distant.See foreground .See middle-distance
a person's social class, education, training, or experience
the social, historical, or technical circumstances that lead up to or help to explain something.(as modifier)
a low level of sound, lighting, etc, whose purpose is to be an unobtrusive or appropriate accompaniment to something else, such as a social activity, conversation, or the action of a film.(as modifier)
Also called: background radiation low-intensity radiation as, for example, from small amounts of radioisotopes in soil, air, building materials, etc
unwanted effects, such as noise, occurring in a measuring instrument, electronic device, etc.(as modifier)