Say a person was really annoying to you and abnoxious won't leave you alone because they where slacking and goofing around touch to go hangout with friends and their the ButMunch.
When someone with a bigbum, swallows things in there bum.
(teacher with a big bum playing badminton)..
"OMG.. she's going to turn around and catch the shuttlecock with her bum!!, Now I know what they mean by butmunch!"
"omg, Shes short..Her bum must have ate her height"
Seemingly derogatory term but often used with affection. In the classic sitcom Malcolm in the Middle, the brothers call each other buttmunch but with a smile and a pat on the back. The word can also be used as a sexually suggestive term, using it on someone you would actually like to munch on your butt.
1. Reese to Malcolm: Way to go buttmunch! I'm proud of you!
2. Reese to Malcolm (pulling down his pants): Hey buttmunch, dive in!