the act of moving/ shaking ones ass/buns/bottom/buttocks/bum-bum in a circular, up-and-down, and side-to-side motion.
basically a slutty dance. derived from strip clubs.
when a girls' ass moves like a bowl of Jell-O
Man: She was twerking so hard on my dick last night! I thought it was gonna go numb!!
Girl: that girl is such a slut for twerking at the dance!