Gross From Up Close - Occurs when an lithesome female is spotted from a distance. When viewed at a closer proximity, it is clear that she is repulsive apart from an attractive figure (ie long legs, curvaceous body).
Viewed from afar, she was a beautiful creature. Upon closer inspection it was discovered that she was "gross from up close".
GFUC is an acronym for Good Far, Ugly Close.
This pertains to a situation where a person seemingly looks attractive from a far distance, from either the front or the back, but in reality, up close, the person is not attractive.
Person 1 to Person 2: "Hey yo, look at that fine ass girl over there!"
-girl walks by-
Person 1: Never mind yo, she's a GFUC.