a reference to a human being that stuffs their fat into a pants size way too small so that their hairy ass crack hangs out.
also a word to describe something very discusting, or to complain.
'Escuse me sir, I'd like to speak with the McManager about these MCNASTY french fries. I'm very unmcsatisfied with their utter mcnastiness.'
'WHOA DUDE! look at that heffer's ass! it's so effin mcnasty. it's a full moon tonight, ehh?'
A horrible and disgusting form of diarrea that fills the whole toilet with its volume and the whole house with its odor; is usually due to consumption of fast food or drinking lots of alcohol the night before.
"Dude, why are you clutching your stomach with one hand and covering your ass with the other?"
"Fuck, I knew I shouldn't have mixed rum with pabst with gin with taco bell with a big mac last night, now I have to take the biggest McNasty known to man."