stopperstop‧per /ˈstɒpə $ ˈstɑːpər/ noun [countable] Word Family: noun: stop, stoppage, stopper; verb: stop, stopper; adverb: non-stop; adjective: non-stopthe thing that you put in the top part of a bottle to close it ⇨ cork—stopper verb [transitive]: a small, stoppered jar