FOS 

Full of shit

Never trust a used-car salesman, they're all FOS.

FOS by Barbarella11 December 21, 2010

FOS 

Abbrev. Full of shit.

FOS by Targen December 2, 2002

FOS 

The acronym for a person who is Full of Shit. When someone is constantly telling outrageous lies, typically about themself, in order to impress others.

"Did you hear that FOS was offered a full scholarship to Harvard, but turned it down to be a UPS driver?"

FOS by Quinn Littles May 14, 2009

FOS 

An abbreviation, meaning "fuckable-on-site". Used to classify extremely sexy people who arouse others to an immediate, uncontrollable frenzy.

Jared Leto (of 30stm) - inherently FOS. No question.

FOS by _Jules_ December 21, 2008

FOS 

Abbreviation: FOS = Full of Shit

• It can mean that someone is lying, therefore full of shit.

• It can also mean the literal aspect, the state of being FOS.
(constipated) or (bowel obstruction)

That patient is totally FOS, just trying to get some drugs.

The patient in room 22 is literally FOS; constipated as hell.

They tried to tell me a BS story about losing their prescription, but I can tell they are FOS.

FOS by Night.ER.Ninja July 27, 2014

FOS 

FOS is short term word said for "Figure of speech", "Figure of speech" is used for like in sentences where your joking.

I'm kms (FOS)

You are idiotic (FOS)

What if i start a cocaine company?🤔 (FOS)

FOS by ShadowOfHallows October 24, 2023

Fos 

fight on sight

yall a bitch ass nigga, yall marked for fight. Fos. fight on sight.

Fos by Racoon_kid March 29, 2019