Pronunciation: Grum-pee. The act of breaking wind; flatulence. A slang term for having particularly foul smelling gas; a nasty stinky fart.
1) Dude, who busted that nasty grumpy.
2) He floated a grumpy in class. Stunk so bad even the teacher left.
3) I suppose if I have to I can live with Bill's farts, but when he floats a grumpy it makes my eyes water and I have to draw the line