Synonyms for Background (same or very similar meaning)
WordNet sense 1 (the state of the environment in which a situation exists):
scope, setting
WordNet sense 2 (extraneous signals that can be confused with the phenomenon to be observed or measured):
background signal
WordNet sense 3 (the part of a scene (or picture) that lies behind objects in the foreground):
ground
WordNet sense 4 (information that is essential to understanding a situation or problem):
background knowledge
WordNet sense 5 ((computer science) the area of the screen in graphical user interfaces against which icons and windows appear):
desktop, screen background
WordNet sense 6 (scenery hung at back of stage):
backdrop, backcloth
WordNet sense 7 (understate the importance or quality of):
downplay, play down
From the ODE community, based on WordNet
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