A girl with whom you had an informal relationship, never quite defining whether or not she was your girlfriend. Stands for "Former Semi Girlfriend"
I went to a few movies with this girl, and then she was like, "I'm goin' out with this other guy!" Now she is my FSGF.
by Ben Cannon May 18, 2005
A girl who beings to go out with 1 of your friends and is a lil bietch so steals your friend from u.
by Snoop April 20, 2005