Open English Wordnet
Nouns
(n)show-stopper, showstopper, stopperan act so striking or impressive that the show must be delayed until the audience quiets down
(n)show-stopper, showstoppersomething that is strikingly attractive or has great popular appeal“she has a show-stopper of a smile”, “the brilliant orange flowers against the green foliage were a showstopper”