knocker

n.[C]

1. 敲擊者；敲擊物
   At the rat-a-tat of the knocker her heart flew into her mouth.

   聽到敲擊者咚咚聲她的心都懸起來了。

2. （敲門用的）門環，門鎚
   There was nothing particular about the knocker on the door, except that it was very large.

   門上的門環沒有什麼特別的，只是很大而已。

3. 【美】【口】吹毛求疵的人
   What a knocker he is; no matter what we suggest, he finds fault with it.

   他真是個吹毛求疵的人；不管我們提議什麼他都能挑出毛病來。

4. 【俚】一對乳房[P]
   She is tall with large knockers.

   她很高，有一對大乳房。