[stop.per] n (15c) 1: one that brings to a halt or causes to stop operating or functioning: check: as a: a playing card that will stop the running of a suit b: a baseball pitcher depended on to win important games or to stop a losing streak; also: an effective relief pitcher
2: one that closes, shuts, or fills up; specif: something (as a bung or cork) used to plug an opening
[2]stopper vt stop.pered ; stop.per.ing (ca. 1769): to close or secure with or as if with a stopper