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."
"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."
by Danny Sin April 16, 2007
by swagmarket October 30, 2009
What the Fuck, he gave me a McNasty
by Bakken March 03, 2009
Someone Who Does it with your ex.. you think shes ugly but shes really pretty but just a rebound girl
by Greys anatomy Fan October 29, 2011
he mcnastyed that trick ass bitch
by Lemony Petaphile June 03, 2008
by JeffReedsGirlx3 January 31, 2009
A female that has taken disgust and grime to an extremity, a true whore at heart that reminds every man of something that can be purchased at mcdonalds; fat, sloppy, and down right disgusting. Generally, if you are indeed dealing with a true McNasty on your hands, chances are that she is so loose that a football can get inserted with zero difficulty.
Guy 1: Wow bro, every time I turn around that girl is hooking up with a new guy. I can't believe you got with her!
Guy 2: I know dude! Chances are I might have an STD...Im pissed.
Guy 1: Yeah dude I'd get checked out tomorrow, what a god damn McNasty
Guy 2: I know dude! Chances are I might have an STD...Im pissed.
Guy 1: Yeah dude I'd get checked out tomorrow, what a god damn McNasty
by President of Piffboro June 06, 2011