BSF 

best sex friend best friend you have sex with

Alt night was great I hung out with my bsf ;)

BSF by Yhnhjk September 5, 2022

BSF 

BallSack Factor
The BallSack Factor is calculated by the difference in the height of your balls divided by the length of your lowest hanging ball. The difference of the balls is measured from the center point of the upper and lower ball. The length is determined by measuring the distance between the base of the ball sack to the lowest point of the ball sack.

BSF = Δballsack / ℓ ballsack

How is your BSF doing? Are you hitting double digits yet?
Almost! My BSF was around 9.7 this morning, what about yours?
No way bro! My BSF was only 0.5 :(

BSF by Monsieur Ballzaque February 13, 2023

BSF 

BSF, acronym. Short for Bud Softball Fan. That guy a woman says is her best friend for making her a softball star, when everyone knows she's ready for some hardball!

It's like Neo, from the matrix always said, "If you call me big papa, and I call you Madame I mean My Dame, I mean Ma Damn! there better not be any BSF laying claim John Wick Zaddy cred... Because I want you in the big leagues, your royal majesty"

BSF by DiamondDouche December 4, 2023

BSF

Brown skin fine

BSF- A brown skin woman who is extraordinarily beautiful

BSF by Joeysanchez34 December 27, 2025

bsf rebound 

person whose being used by their best friend because they don’t have a bf/gf

person 1) i feel like kelly only really talks to me when she’s single
person 2) she’s found her bsf rebound ig

bsf rebound by hottestmilfoat January 19, 2023

bsf bc 

bsf= bestfriends

bc=brother crush

so this basically means that you have a crush on your best friends older or younger brother...

woah you have a bsf bc
yeah...
you should tell your bsf

bsf bc by brook;)) October 21, 2020

Bsf hug day 

On April 24th everyone can hug their closest friends to show that they are their favorites

"Hey isn't Lisa ur best friend?then hug her Duhh it's bsf hug day"

Bsf hug day by Whatthiscrazy65 May 29, 2018