similar to the commonvaginal "fart" or "queef"... BUT (no pun intended) is different in the fact that it is expelled from the anus rather than the vagina.
Timmy pulled his cock out of Johnny's ass and was surprised by the expulsion of air between Timmy's cheeks...
"I swear it wasn't a fart, it was just a buqueef."
the occurrence of a man farting, accidentally or otherwise, on a close friend who is also male.
While playing the fast-paced action video game, Halo Reach, Carlos failed to score the game-winning frag for his team, as he was distracted by Todd's pestilent buttqueef.