The Collaborative International Dictionary of English v.0.48:
Stifler \Sti"fler\, n. 1. One who, or that which, stifles. [1913 Webster] 2. (Mil.) See Camouflet. [1913 Webster]WordNet (r) 3.0 (2006):
stifler 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]