FNS 

Generally, to screw someone or something over, or otherwise mess things up (such as plans or a game). Can be used interchangeably with Bullshit.

Darren: Hey man, I'm on our way
Madonna: Oh, well I'm about to leave
Darren: What? You said you were gonna be there for awhile
Madonna: Yeah but I got bored
Darren: This is some FNS, man

FNS by fadu09 April 1, 2010

FNS 

A living hell. Given by teachers that are PMSing or being bitchy (they think you have done something "wrong"). Given on Friday nights after school ends, you are forced to go sit in a room, with strangers, and do nothing. The most common forms are 4 hours and 2 hours. FNS stands for Friday Night School.

me: "OMG! I just got a fucking FNS! My math teacher is a bitch, I didn't even to anything!!! I am so not going to that bitches FNS!"

friend: "what the? That sux, if you don't go you'll get an ISD!"

me: "screw that fucking bitch!"

FNS by fuckingworld November 20, 2007

FNS 

An acronym for Fat Nigger Slut.

Commonly used by white people.

GET THAT FNS

FUCKING NIGGERS

FNS by DJ JAM JAM June 6, 2017

FNS 

it’s like MCM or WCW but it’s FNS Fine Nigga Saturday

who wants to be my FNS ??

FNS by sandy cheeky February 15, 2019

FNS 

Fuck Nigga Shit- somebody doing the most/too much, somebody doing something unnecessary, stupid or messing up the vibe.

josh: omm he on that fns
will: wym
josh: he always doin sum stupid or doing unnecessary shit.

FNS by princesscici October 5, 2020

FNS 

Fuck Nigga Shit: Somebody doing the most/too much, somebody doing unnecessary shit, or somebody messing up the vibe.

Kiki: Ole dude on that fns

Timi: whats fns?
kiki: fuck nigga shit.... he be doin the most and ruining the vibe.... he gomn.

FNS by princesscici October 5, 2020

FNS 

Fart n shart

Guess I'll FNS ass

FNS by Fartnshartass May 2, 2022