quite simply, Friend Of Girl... a guy who simply can not seal the deal with the ladies, or one who tries to befriends first and then develop the relationship but fails in the latter.
"fresh out of grade school." Basically, a grade nine, or when someone acts immature. It is interchangeable with the term "niner" only FOG is more fun to say...
-(Let's say Jill is actingimmature), One may say, Jill is so FOG.
/fôɡ/ : a friend of the gays; or questionably straight men with perfect hair and impeccable style who partake in activities such as shopping and SoulCycle, and appear to be gay in every way, but have girlfriends.