Sports To defeat (a boxing opponent) by a knockout.【体育运动】 击倒对手：通过击到对方而击败（拳击比赛中的对手）
To render useless or inoperative:使无用，使失去效能：The storm knocked out the telephones.风暴使电话中断
Informal To exert or exhaust (oneself or another) to the utmost:【非正式用语】 尽心尽力：最大程度地努力或用尽（自己或别人的）力量：knocked herself out to be ready on time.为了及时作好准备她竭尽全力