knockers

1. A device, usually hinged with a striking plate, used for knocking on a door.
2. A person who knocks.
3. A critic; one who disparages.
4. A person who knocks (denigrates) something.
5. (usually in the plural) A woman's breasts.
6. (especially Cardigan) A dwarf, goblin, or sprite imagined to dwell in mines and to indicate the presence of ore by knocking.
7. A mechanical device in a pinball table that produces a loud percussive noise.
8. A person who is strikingly handsome or otherwise admirable; a stunner.
9. A large cockroach, especially Blaberus giganteus, of semitropical America, which is able to produce a loud knocking sound.
10. A large, boulder-shaped outcrop of bedrock in an otherwise low-lying landscape, chiefly associated with a mélange.
11. One who defaults on payment of a wager.

noun

A woman's breasts.