0 in boxing, the act of hitting the other fighter so that they fall to the ground and are unable to get up again within ten seconds -- (拳击中的)击败对手的一击,击倒对手获胜
1 a competition in which only the winners of each stage play in the next stage, until one competitor or team is the final winner -- 淘汰赛
a knockout competition/championship 淘汰赛/锦标赛
The tournament is a straight knockout. 这次锦标赛是直接淘汰赛。
2 a person or thing that looks, sounds, etc. extremely attractive -- 极有吸引力的人(或物)
Your sister's a real knockout! 你的妹妹真是令人着迷!
3 extremely attractive -- 极有吸引力的