to bring a result opposite to that which was planned or expected.

v. collectively or individually finding someone/something to blame for a problem, as opposed to brainstorming which connotes finding solutions to a problem

n. the act of finding someone/something to blame for a problem

(from a TV ad for HD television)

The moment where, when you're taking a shit, a large pocket of gas (referred to as a future-fart) that was resting mid-shit or between two shits escapes as you're passing your lovelog, resulting in a sudden violent fart than not only propels your previously freefalling turd at Mach 2 speeds, but also results in a pleasing shotgun blast of turdlings across the toilet bowl.

A backfire is so named for it's similarity to a car backfiring.

The prefix given to an internet thread predicting the future that fails miserably, causing lulz.

When you're about to fart, and something extra (and usually liquid) explodes out of the ass.

When a man is receiving a blowjob and upon finishing inside the mouth of the giver, the contents are spat back in his direction.

After a really serious depressing prediction about the future of an old pensioners death the definition is when the old pensioner makes a funny remark which ruins the seriousness and brings the convocation back to normal levels.