The Collaborative International Dictionary of English v.0.48:
Bunghole \Bung"hole`\, n. See Bung, n., 2. --Shak. [1913 Webster]WordNet (r) 3.0 (2006):
bunghole n 1: vulgar slang for anus [syn: arse, arsehole, asshole, bunghole] 2: a hole in a barrel or cask; used to fill or empty it