background
back·ground / ˈbakˌground/ • n. 1. [in sing.] the area or scenery behind the main object of contemplation, esp. when perceived as a framework for it: the house stands against a background of sheltering trees. ∎ the part of a picture or design that serves as a setting to the main figures or objects, or that appears furthest from the viewer: the background shows a landscape of domes and minarets the word is written in white on a red background. ∎ a position or function that is not prominent or conspicuous: after that evening, Athens remained in the background.2. the general scene, surroundings, or circumstances: the black cab blends beautifully into the city background. ∎ the circumstances, facts, or events that influence, cause, or explain something: the political and economic background ∎ a person's education, experience, and social circumstances: she has a background in nursing a mix of students from many different backgrounds.3. a persistent level of some phenomenon or process, against which particular events or measurements are distinguished, in particular: ∎ Physics low-intensity radiation from radioisotopes present in the natural environment. ∎ unwanted signals, such as noise in the reception or recording of sound.4. Comput. used to describe tasks or processes running on a computer that do not need input from the user: programs can be left running in the background.