knockout

noun

1 forty-three of Rocky's matches were won by a knockout:

stunning blow, finishing blow;

French coup de grâce;

informal KO, kayo.

2 before the third round knockout punters were growing bored:

elimination match, tie, elimination competition.

3 informal she's nice-looking but not a knockout:

beauty, vision, picture, sensation, joy to behold, dream;

informal stunner, dish, looker, good-looker, lovely, peach, eyeful, smasher, cracker.

4 informal the binoculars are a technical knockout:

masterpiece, sensation, marvel, wonder, triumph, winner, success, feat, coup, master stroke;

smash hit, hit, attraction;

French tour de force, coup de maître;

informal smasher, cracker.

▷antonyms failure, flop.

knockout Oxford Dictionary of English