Green’s Dictionary of Slang

gangie v.

[gangie n. (1)]

(Aus.) of a woman, to make oneself available for sex with a number of men in sequence.

[Aus]Tracks (Aus.) Oct. 82: One roots, one gives head [i.e., fellates] and the other gangies [?makes herself available for a gang-bang — i.e., where several males have sexual intercourse seriatim with one female] [Moore 1993].