Girl Friend Forever.
A play on BFF or best friend forever. Basically implies that you'll never marry the person your with but still reap the benefits of being married without the commitment.

I love Susan but we'll never get married, she's my GFF.

GFF by JoeyBallard April 13, 2011

Gff

Great. Fucking. Feeling

That was a Gff I had last night

Gff by Ima_failure December 30, 2018

GFF

A feminine refinement of BFF, meaning GirlFriends Forever.

"Lauren and me have known each other since we were, like, little, and we are, like, GFF."

GFF by Monkey's Dad August 22, 2021

GFF

Golfing Friends Forever - a take off of "BFF." A friendship between a group of mails forged on the golf course. Because these men aren't comfortable being categorized as "best friends," the more masculine addition of golf is an acceptable way to label the relationship without hinting to any sort of level of disclosure or friendship.

Dave wouldn't meet the other dads in the neighborhood for conversation and coffee, but he was comfortable playing golf with them. In fact, I think he considers them to be his GFFs.

GFF by The Quipster June 15, 2013

GFF

Gamingforce Interactive Forums. An elitest hellhole of a forum where the regulars flame newbies every day, the elitests themselves decide when you are finally "cool" after acquiring a "reputation" of said coolness. This only occurs after a lengthy period of time has passed (Years). Owned by an extremely ugly looking asian man.

(Newcomer who just registered): "This seems like a nice video game forum. I think I'll make my intro thread."

After making intro thread...ten replies have been made, the latest one being an elitest like a lurker, Sassafrass, others...

Elitest reply: "Hey newbie, you like video gams and anime, huh? FUCK OFF THEN!!"

Upon reading that, the newcomer never sets foot in GFF ever again.

GFF by Mr. Bird January 28, 2005