A fart that sneaks out the front. This phenomenon usually occurs while seated. The fart gets trapped in the butt cheeks and slowly makes it way out the front instead of the back. A slight tickling sensation may be felt as the air bubble makes it's journey from anusville through grundle town.
Steve: Damn Gina, Did you just queef? It smells a used diaper filled with Indian food!
Gina: No, that was a butt queef! I tried to sneak a fart out and it came out the front. I guess that curry slurpee was a bad idea!
Unlike a fart, when air gets trapped in one's butt cheeks, usually while sitting, and a small pocket of air pops out. This is similar to a vaginal queef.
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.