Green’s Dictionary of Slang

gee n.4

[? Irish sl. gowl, the vagina; ult. Irish gabhal, the fork (of the body)]

1. a woman considered solely as a sex object.

[Ire]R. Doyle Commitments 6: The brassers, yeh know wha’ I mean. The gee.
[Ire](con. 1916) R. Doyle A Star Called Henry (2000) 153: Too much of the gee, he said.

2. (also gee box) the vagina; also attrib.

[Ire]S. Beckett Dream of Fair to Middling Women (1993) 71: Lilly Neary has a lovely gee.
[Ire]R. Doyle Van (1998) 406: But he’d had to keep feeling them up and down from her knees up to her gee. [Ibid.] 531: Bending over so he could see the water dripping off their gee hairs.
[Ire]G. Coughlan Everyday Eng. and Sl. [Internet] Gee, Gee-box (n): female genitalia.