BSF 

Big Straight Facts-These are facts that are the realest and truest of facts. There is no falsification within these facts.

Jim: Wow. My life kind of sucks right now.
Carey: Thats BSF!!!

BSF by acronymgoddess December 14, 2018

BSF 

Butt sex friend.

A friend you have butt sex with. Could be male or female. That is my BSF.

BSF by The real urban December 20, 2017

BSF 

inshort, best stranger forever.

bobo, at&t, and deedee are my bsfs!

BSF by urnecksmeller(= June 18, 2008

Bsf 

A best friend a really good friend,her name has to be kenzi because they are the best best friends ever!

Hey I got a good bsf !who is it ?her name is kenzi!wow I’m not surprised

Bsf by Strizak November 22, 2019

Bsf 

Best shitty friends

Your my bsf

Bsf by yaga420 October 25, 2018

BSF 

A Back Stabbing Friend

Caroline was a BSF cause she lied to make the team

BSF by Brynn the girl who was stabed March 15, 2019

BSF 

Boston Sports Fan
Someone who cheers for the Patriots, Celtics, Bruins, and Red Sox either by choice or by default (someone who is originally from Boston or has lived in Boston at one point in time).

"You're not watching the Patriots? Just because you're in New York doesn't mean you can abandon your BSF duties."

BSF by Gildey December 21, 2015