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1.
A lingering smelly fart
You farted 10 minutes ago? Yea. Jesus this butt fog just wont go away!!
by Sirweighalot March 18, 2009
 
2.
fart, flagalance, to bust ass, pretty much when you blast a fog horn in your pants and crop dust a layer of fog behind you creating low breathabilty possibly causing nausea leading to poor visability
After Betty destroyed the bathroom, she walked down the hall leaving a musky layer of butt fog causing fellow co workers to feel sick.
by greater good July 31, 2012