Urban Dictionary: BSF

Best sister/friends
When two best friends are so close that they consider themselves as sisters !

- Pauline and Catherine are really close!
- Yeah! They're BSF s :)

by foreveryounnng May 12, 2012

A bsf means best friend usually, bsf can mean a best friend who is like a sibling to you or just a best friend

by Your_Dictionary April 14, 2019

by Kiahhh February 23, 2018

"Bull Shit Foursome"
Four friends who often go out together on random crazy adventures and day trips.

Let's go out BSFing this weekend!

by Cindy5 January 24, 2009

How low do you hang?
Ball Sag Factor

How's the BSF today?

by FactRzerO August 01, 2003

The cliched phrase every guy tells to a girl when he wants her: Beautiful, Smart, and Funny.

Hey bro, did she say yes?
Nah, I did the BSF way too early

by Kukoo October 09, 2010

Someone who is a BOOB STARING FREAK. Usually straight guys.