background

adj

1. (not-comparable)Less important or less noticeable in a scene or system.

   “background noise”

   “The antivirus program runs on a background thread.”

noun

1. (countable, uncountable)One's social heritage, or previous life; what one did in the past.

   “The lawyer had a background in computer science.”

2. (countable, uncountable)A part of the picture that depicts scenery to the rear or behind the main subject; context.

   “Earless ghost swift moths become “invisible” to echolocating bats by forming mating clusters close[…]above vegetation and effectively blending into the clutter of echoes that the bat receives from the leaves and stems around them. Many insects probably use this strategy, which is a close analogy to crypsis in the visible world — camouflage and other methods for blending into one’s visual background.”

3. (countable, uncountable)An extra who appears in the background, with no speaking role.
4. (countable, uncountable)Information relevant to the current situation about past events; history.
5. (countable, uncountable)A less important feature of scenery (as opposed to foreground).

   “There was tons of noise in the background.”

   “The photographer let us pick a background for the portrait.”

6. (countable, uncountable)The image or color over which a computer's desktop items are shown (e.g. icons or application windows).
7. (countable, uncountable)A type of activity on a computer that is not normally visible to the user.

   “The antivirus program is running in the background.”

8. (abbreviation, alt-of, countable, ellipsis, uncountable)Ellipsis of background radiation.

   “low-background”

verb

1. (transitive)To place in the background.

   “Ha! I see Venus’ transit now;—lo! a new planet there;—and behind all, an infinite starry nebulousness, as if thy being were backgrounded by some spangled vail of mystery.”

2. (figuratively, transitive)To put in a position that is not prominent.

   “One aspect of the story that appears interesting is that the alleged rapist and victim are only referred to by name together in the same sentence once. In all the other sentences, one receives more focus, while the other is backgrounded.”

3. To gather and provide background information (on).
4. (transitive)To increase the weight and immunity of (a calf) by feeding with forage and grains, as an intermediate stage in cattle production, between weaning and placement in a feedlot.
5. (form-of, participle, past)simple past and past participle of backgrind