stopper (n.)

late 15c., "one who obstructs," agent noun from stop (v.). From 1590s as "something that obstructs;" specific sense "glass plug for a bottle neck" is from 1660s. As a verb from 1670s. Related: Stoppered.

Definitions of stopper
stopper (n.)
an act so striking or impressive that the show must be delayed until the audience quiets down;
Synonyms: show-stopper / showstopper
stopper (n.)
a remark to which there is no polite conversational reply;
Synonyms: conversation stopper
stopper (n.)
(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
stopper (n.)
blockage consisting of an object designed to fill a hole tightly;
Synonyms: plug / stopple
stopper (v.)
close or secure with or as if with a stopper;
The mothers stoppered their babies' mouths with pacifiers
She stoppered the wine bottle
Synonyms: stopple