Green’s Dictionary of Slang

(US) an act of usu. non-consensual intercourse, involving a number of men and a single woman.

1971		R.D. Pharr S.R.O. (1998) 301: Why the hell didn’t they throw her down and do a gang job? That’s what they wanted to do.
1985		Tracks (Aus.) May 32: Me and the lads used to go down to King’s Beach (Caloundra) for a smoke and a gang with the local snatch [Moore 1993].