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
Verb. The act of going out clubbing or dancing. It is derived from the word "Unce" which is most associated with the sounds at EDM, Digital, and Techno concerts.
Do you want to gounceuncing in the City this Friday?