Non Caucasian Gash; an attractive woman of any racial classification other than white. Includes black women, middle eastern women and even hispanic women, but is most commonly used to refer to a woman of far-eastern extraction.
It is generally meant as a compliment, although some women see it as derogatory, misogynistic and offensive.
"Shit, check out the massive arse on that NCG. En see geeeeeeeeeeee!"