A term used to refer to a 30mg perscription pain pill, specifically an oxycodone hydrochloride 30mg tablet. Other examples are Roxies, and Blues.
Mike: Yo, you think you can front me a 30, Dawg?
Vince: Hell no, you still owe me from last night! Come back with $20 and you can get one though.
Mike: C'mon, man. I'm dope sick.