A trustafarian is a spoiled rich kid most often still in college who decides to adopt a neo-hippie lifestyle to fit in and because their parents are supporting them with money which is then used to buy drugs. This way trustafarians can afford to go to jam band concerts and dance like a prick, and generally become a complete burnout on their parents tab. In a rather ironic twist some trustafarians were former fraternity/sorority members and have decided to discard their former conservative ideals all to common within the greek system and a adopt a more progressive liberal outlook. All in the pursuit of the next drug and alcohol bender courtesy of daddy's credit card.
Serious student: Man this marketing test tomorrow is gonna kill me. I've been studying all night!
Trustafarian: No way bro! I'm hitting up Phish tonight. Gonna be absolutely filthy. Trey is gonna melt my face. Gonna straight RAGE! Already got my goody bag ready for the show if you know what I mean.
Serious student: Wow... his dad even PAYS him to be a piece of shit.