knocker
n
1 [C] hinged metal hammer attached to a door, used for knocking by sb outside who wants the door to be opened 门环. =>illus at App 1 见附录1插图, page vi.
2 [C] (infml 口) person who constantly criticizes 一味批评的人; 吹毛求疵的人.
3 knockers [pl]
( Brit sl sexist 讳, 俚, 性别偏见) woman´s breasts 女子的乳房
a nice pair of knockers 一对漂亮的乳房.