Top Definition
The nasty, scumy, build up of sweat, crusted feces and other various substances in and around one's anus. Usually an indicator of uncleanliness and/or failure to correctly wipe one's rectum after defecation.
"Frank you need to wipe man, I smell that ass nast from all the way over here!"
by B729 November 27, 2007

Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from We'll never spam you.