Wordnet 3.0
NOUN (1)
1. 
 a person who stifles or smothers or suppresses; 
- Example: "he is a real conversation stifler"- Example: "I see from all the yawn smotherers that it is time to stop"[syn: stifler, smotherer]
WordNet (r) 3.0 (2006):
smotherer
    n 1: a person who stifles or smothers or suppresses; "he is a
         real conversation stifler"; "I see from all the yawn
         smotherers that it is time to stop" [syn: stifler,
         smotherer]