Brisbane, Australia. Slang for a juvenile delinquient, though may age as far as late-20's. They're typified by poor personal hygene, low education, violent demeanour and a proliferation of trolley-handles (bars) as weapons. They steal, they kill, they cause trouble. Term arised from their most common phrase, "Gotta darb, cuz/cunt?"
A darb tried to drag me in his Commodore when I was driving through Wynnum.