bump

Concise Oxford English Dictionary © 2008 Oxford University Press:
bump/bʌmp/

▶noun

• 1 a light blow or a jolting collision.

  ■ Rowing (in races where boats make a spaced start one behind another) the point at which a boat begins to overtake or touch the boat ahead, thereby defeating it.

• 2 a protuberance on a level surface.

  ■ dated a lump on a person's skull, formerly thought to indicate a particular mental faculty.

• 3 Aeronautics a rising air current causing an irregularity in an aircraft's motion.

▶verb

• 1 knock or run into with a jolt.

  ■ (bump into) meet by chance.

  ■ Rowing gain a bump against.

• 2 move or travel with much jolting.

• 3 (bump someone off) informal murder someone.

• 4 (bump something up) informal make something larger or appear to be larger.

• 5 refuse (a passenger) a reserved place on a flight because of deliberate overbooking by the airline.

  ■ N. Amer. displace from a job or position.

– origin C16 (as v.): imitative, perh. of Scand. origin.