stopper - noun

an act so striking or impressive that the show must be delayed until the audience quiets down

a remark to which there is no polite conversational reply

(bridge) a playing card with a value sufficiently high to insure taking a trick in a particular suit

blockage consisting of an object designed to fill a hole tightly

stopper - verb

• close or secure with or as if with a stopper

stopper - thesaurus

plug   showstopper   stopple