MSF 

My Space Friend; People you add to your profile that you call friends.

Jenny is Kirsten's newest MSF.

MSF by Jenn W. August 3, 2007

MSF 

Male Sexual Frusteration...the one week a month a guy get his chance to bitch never ending about shit

Take that women

Steve: Man that pisses me off!!!
Dan: What is wrong with you? it it MSF time?

MSF by 2 Stale Crackers March 9, 2009

MSF 

Mean Sober Friend. Someone, in a group of people drinking and having fun, that is unhappy and angry.

When a man is talking to a group of women (can be generalized to other social interactions), sometimes one woman, usually the least attractive of the group, is not getting enough attention. While everyone else is laughing and having fun, she tries to interrupt by saying, "let's go somewhere else," or "I'm tired;" or verbally attacks the male suitor. She is an MSF.

MSF by Jerry406 November 17, 2007

Msf 

Mega sad face

Louis Theroux is married msf

Msf by cazzadelrey November 2, 2017

msf 

abbreviation of "myself"

i identify msf as kilometres per second cuz i want to km/s

msf by benzoganger February 20, 2024

MSF 

Militaries Sans Frontiers-private military company made by Big Boss during the events of MGS: Peace Walker. Predecessor of Outer Haven.

"We've come to you-Militaries Sans Frontiers for help" MSF

MSF by doobi January 26, 2025

MSF High 

An obscure transformation fetish webcomic on DeviantArt that has incredibly deep and in-depth lore for some unexplainable reason.

"MSF High is such a weird read. On one hand, it's clearly made by and for transformation fetishists to rock their socks off to, but on the other hand the lore is actually super well written and really in-depth."

MSF High by KrimsonKatt January 13, 2022