Mainly used as a term while drunk/drinking. Used in place of names such as bro, dude etc. Also can be used as a verb to describe the art of getting heavily drunk. Can also be interchanged for most other English words (see example)
1) Man, I was so bunced last night at that party.
2) Bunce up to my place now, bro!
3) Let me snaffle some bunce-juice and bunce my bunce up to bunce's to get bunced.