When a fat chick uses deceptive camera angles and lighting to hide the fact that she's a blimp, and make you think she's actually hot.
"WTF, but she looks hot in her default!"
"Of course she does, it's an FGAS."
"I have been deceived."
Example: "I have no idea what you look like, due to your shitty FGA pictures."
This occurs when,
A.) A fat girl takes a picture of herself, then crops out the body, leaving her face.
B.) A fat girl takes a picture of herself from an angle, trying to look 'skinnier'. See epic fail
C.) A fat girl gets her friend to take a picture of her, then using a crappy shooping program to make sparkly glitters appear in every where in the picture, EXCEPT HER FACE.
(not to be confused with fags)
Person 2: Oh yeah, she was totally hawt.
Person 1: Yeah! Hey Person 3, c'mere!
*person 3 looks at picture*
Person 3: NAWWW MAN, THAT BE A FGAS!!!