Although a shortened form of faggot, offensive slur of homosexuals, it's often used to disparage men who are perceived to be weak. This definition can be extended to someone who's annoying like Harley riders as aptly described in a South Park episode and is British slang for a cigarette. Many rappers like Eminem normalized the use of the word to label weak men/frauds.
As Eminem explained you can be gay, but that doesn't make you a fag as your actions as a weak poser does. Many closet homosexuals that are gangsters and frat boys are huge fags as they like to stalk/harass attractive men. Police officers that beat men and stalk/harass guys trying to get them arrested on petty violations, especially men of color for no apparent reason are huge fags!
A guy look so damn ugly (bad genetics) that he wouldn't have a chance to get a girl at all. Slim to none.
These guys girls quietly think he fag always get rejected by girls all the times. No hope. He knew what girls are thinking and girls won't admit why she rejected him first place.
Girl1: (look at that ugly guy picture on dating app) I won't date that guy. He looked so fag. Do you have any good looking guy I can hangout with.
Girl2: Yeah. Check this out the guys I chatted with. You can have him he look handsome.
Girl1: OMG he so rad!! Going to find him and msg him! Thanks you my bestie!
Krillin: He looks like a total FAG Gohan: KRILLIN!
Krillin: What? a Frealy Alien Genotype, what’d you think i meant?
Gohan: Oh, i thought you were calling him a derogatory term for homosexual…
Krillin: THAT THING’S A GUY?!?!?!