noun

1. a person who rocks a cradle, etc.
2. either of the curved pieces on the bottom of a cradle, rocking chair, etc.
3. ☆ rocking chair
4. a cradle for washing sand or gravel in gold mining
5. a small steel plate with a toothed and curved edge, for roughening and thus preparing the surface of a mezzotint plate
6. one of the curved stripes below the chevron of a noncommissioned officer above sergeant
7. ☆ Informal
   1. a performer, fan, etc. of rock music
   2. a rock song performed with a heavily accented rhythm at a fast tempo