look up any word, like ratchet:
 
1.
To wreck, or fuck something up. Doing a horrible job on something.
Man you bonanged my car, its falling apart!
by Mike W Anarchy November 25, 2007
 
2.
a really really reallly fat person that can't sit on a desk without falling off it
holy shit look at that bonang she can't even sit on that damn desk
by Killjoy123 October 21, 2007