Bump

1. A protuberance on a level surface. He discovered a bump on his arm.
2. A light blow or jolting collision. He bumped his head on the doorway.
3. A temporary increase in a quantity, as shown in a graph. He got a bump in the approval survey.
4. The sound of a collision. We heard a loud bump outside our window.
5, To deprive a passenger of a reserved seat because of overbooking. They had to bump three passengers from that flight.