beater

1. Someone or something that beats.
2. A kitchen implement for mixing.
3. A stick used to play a percussion instrument.
4. A person who drives game towards shooters in a hunting party, often working in a group.
5. A papermaking machine for processing fibres by fibrillation in order to improve bonding strength
6. An automobile in poor operating condition.
7. A weaving tool designed to push the weft yarn securely into place. It contains the comb-like insert reed and is sometimes a part of the loom.
8. A harp seal pup after its first moult and before its second moult.

noun

A sleeveless undershirt.