What is Bump ?
Bump is (noun) 1. a slight knock The boat hit the landing stage with a bump. 2. a raised place Drive slowly, the road is full of bumps. 3. a raised place on your body, where something has hit it He has a bump on the back of his head. ((verb)) to hit something or a part of the body He’s crying because he bumped his head on the door.
source: Easier English, Student Dictionary Upper Intermediate Level