1.使不省人事；使入睡Toknock someoneout means to cause them to become unconscious or to go to sleep.

e.g. He was arguing with his girlfriend and she hit him with a frying pan! Nearly knocked himout...他和女友争吵时女友竟拿煎锅砸他！几乎把他砸晕了过去。e.g. The three drinks knocked himout...3杯酒就让他昏昏入睡了。

2.击败；淘汰If a person or teamis knocked out of a competition, they are defeated in a game, so that they take no more part in the competition.

e.g. Henri Leconte has been knockedout in the quarter-finals of the Geneva Open...亨利·勒孔特在日内瓦公开赛四分之一决赛中被淘汰。e.g. The Irish came so close to knocking Englandout of the European Championships.爱尔兰队险些将英格兰队从欧锦赛中淘汰出局。

3.摧毁；使瘫痪If somethingis knocked out by enemy action or bad weather, it is destroyed or stops functioning because of it.

e.g. Our bombers have knockedout the mobile launchers...我们的轰炸机摧毁了移动火箭发射台。e.g. A storm has made roads treacherous and knockedout power.一场暴风雨致使公路隐患重重且电力瘫痪。