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."