Definitions
1.NounA device, usually hinged with a striking plate, used for knocking on a door.
2.NounA person who knocks.
3.NounA critic; one who disparages.
4.NounA person who knocks (denigrates) something.
5.NounA person's breast, especially if large.
6.NounA dwarf, goblin, or sprite imagined to dwell in mines and to indicate the presence of ore by knocking. .mw-parser-output .defdate{font-size:smaller}
7.NounA mechanical device in a pinball table that produces a loud percussive noise.
8.NounA person who is strikingly handsome or otherwise admirable; a stunner.
9.NounA large cockroach, especially Blaberus giganteus, of semitropical America, which is able to produce a loud knocking sound.
10.NounA large, boulder-shaped outcrop of bedrock in an otherwise low-lying landscape, chiefly associated with a mélange.
11.NounOne who defaults on payment of a wager.
12.NounA gun.
13.NounAn undercover policeman.