Top Definition
1. Exceedes societal norms of acceptable grossness.
Did you see that photo of Amy Winehouse going to rehab?

Yeah, that was mass nast.
by jimmy b and matt e January 22, 2008
5 Words related to mass nast

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.