look up any word, like sex:
 
15.
the doing of sexual intercourse while on the roof of toys r us while giving your partner a texas chili bowl and singing old elvis songs
Cody Houck decided to go on the roof and mcnasty rebel
by Josh Chotta January 17, 2007
 
16.
something that is so unbelievable, that its better than awesome
Thats so mcnasty!, Aaron won the lottery.
by The Real Pab June 23, 2006
 
17.
This is when a male picks up a female at a fast food restaurant like MacDonald's. Usually there are other disturbing things involved with the incident.
The other day my friend went to MacDonald's for some post drinking treats and he got a McNASTY to go...hold the fries.
by Chuck June 10, 2004
 
18.
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
by President of Piffboro June 05, 2011
 
19.
Ordering a McDouble and a McChicken, then putting both patties between one set of buns, to create one nasty sandwich.
After the bar last night, I went and got a McNasty and 10 piece McNuggets.
by sirpilf March 14, 2010
 
20.
Too be excetionally nasty, grimy, or just down right dirty.
Joe has a very McNasty swag.
by swagmarket October 29, 2009
 
21.
When a guy nails a chick in the ass and then she sucks his cock.
Guy 1: Dude, did you really give her a McNasty?

Guy 2: Hell yeah!
by dafrog_05 March 16, 2009