Rocker is a term with multiple meanings:
1. A musician who plays rock music or a fan of rock music
2. A member of a rocker subculture, especially in the UK during the 1960s
3. The curved piece on the bottom of a rocking chair or cradle that allows it to rock back and forth
4. In mechanical engineering, a rocker is a component that rocks or swings
5. In surfing, a rocker refers to the curve of a surfboard from nose to tail