For years round here I've hear the word 'Chad' used for backside. I also heard Joe Pasquale once use it on TV.
Has anyone else heard it used and where does it come from. I think its gypsy talk as I know Joe P has gypsy heritage and we're not short of a few round here!
There are loads of slang meanings for chad on the Urban Dictionary web-site, but none refers to backside.
Chad Valley was (is?) the name of a major toy manufacturer, so it occurs to me that the valley aspect might have been a reference to bum-cleavage! Just a thought.