英汉词典

1. 敲；击
    If you knock on something such as a door or window, you hit it, usually several times, to attract someone's attention.

    e.g. She went directly to Simon's apartment and knocked on the door...
           她直奔西蒙的房间，敲了敲门。
    e.g. Knock at my window at eight o'clock and I'll be ready...
           8点钟敲我的窗，我会准备好的。