Unce

An adjective and verb, the word "Unce" is used, in adjective form, when something can't simply be described as cool. In verb form, "unce" means that you're going to do something to near perfection.

Friend: Dude, I just fucked the biggest tits in my life
Other Friend: Yooooooooo, that's mad unce

in verb form

Friend: Dude, you gonna fuck it up tonight?
Other Friend: I'm gonna be uncing this shit tonight.