Definition of "Stopper" :

noun: blockage consisting of an object designed to fill a hole tightly

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

"If my partner has a spade stopper I can bid no trump."

noun: a remark to which there is no polite conversational reply

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

verb: close or secure with or as if with a stopper

"She stoppered the wine bottle."