bump / bəmp/ • n. 1. a light blow or a jolting collision: a nasty bump on the head. ∎  the dull sound of such a blow or collision. ∎  Aeron. a rising air current causing an irregularity in an aircraft's motion.2. a protuberance on a level surface: bumps in the road. ∎  a swelling on the skin, esp. one caused by illness or injury.• v. 1. [intr.] knock or run into someone or something, typically with a jolt: I almost bumped into him. ∎  (bump into) meet by chance: we might just bump into each other. ∎  [tr.] hurt or damage (something) by striking or knocking it against something else: she bumped her head on the sink. ∎  [tr.] cause to collide with something: she went through the door, bumping the bag against it.2. [intr.] move or travel with much jolting and jarring: the car bumped along the rutted track. ∎  [tr.] push (something) jerkily in a specified direction: she had to bump the wheelchair down the steps.3. [tr.] refuse (a passenger) a reserved place on an airline flight, typically because of deliberate overbooking. ∎  cause to move from a job or position, typically in favor of someone else; displace: she was bumped for a youthful model.PHRASAL VERBS: bump someone off inf. murder someone.bump someone up inf. move someone to a higher level or status; promote: he was a writer for nine years before he was bumped up to editor.bump something up inf. 1. make larger, greater, or more numerous; increase: they finally agreed to bump up her salary.2. make, complete, or release earlier than planned or expected: the date of publication was bumped up to coincide with the grand jury investigation.

bump imit. of a heavy dull blow; its result, swelling, protuberance. XVI. The sb. and vb. appear about the same time; perh. of Scand. orig.; cf. MDa. bumpe strike with fist.
Hence bump vb. †swell, bulge XVI; strike heavily XVII. bumper full glass of drink XVII; anything unusually large XIX; f. †bumping (XVI) prp. adj. huge, ‘thumping’.