The Collaborative International Dictionary of English v.0.48:
Stopper \Stop"per\, v. t. [imp. & p. p. Stoppered; p. pr. & vb. n. Stoppering.] To close or secure with a stopper. [1913 Webster]WordNet (r) 3.0 (2006):
stoppered adj 1: (of a container) having a stopper in the opening; "the tightly stoppered bottles"