Wordnet 3.0
VERB (1)
1. 
 fill or close tightly with or as if with a plug; 
- Example: "plug the hole"- Example: "stop up the leak"[syn: plug, stop up, secure]
WordNet (r) 3.0 (2006):
stop up
    v 1: fill or close tightly with or as if with a plug; "plug the
         hole"; "stop up the leak" [syn: plug, stop up,
         secure]