knockout
     adj : very strong or vigorous; "strong winds"; "a hard left to the
           chin"; "a knockout punch"; "a severe blow" [syn: {hard},
            {severe}]
     n 1: a very attractive or seductive looking woman [syn: {smasher},
           {stunner}, {beauty}, {ravisher}, {sweetheart}, {peach},
           {lulu}, {looker}, {mantrap}, {dish}]
     2: a blow that renders the opponent unconscious [syn: {KO}]
Source: WordNet® 2.0