Green’s Dictionary of Slang

1. (US) a pretty young woman [var. on peach n.¹ (1)].

1902		Ade Girl Proposition 122: I want you to see this Nectarine that I’m tied up with.
1914		Ade ‘The New Fable of the Private Agitator’ in Ade’s Fables 7: The Niftiest Nectarine that ever came down a Crystal Stairway from the Celestial Regions.

2. (S.Afr. gay) a smooth, hairless anus.

2003

K. Cage Gayle 84/2: nectarine n. smooth, hairless anus (1 prefer nectarines to mangos).