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?"
by Quinn Littles May 14, 2009
Get the FOSmug. 
by Ty Chapman May 4, 2005
Get the fo'mug. An abbreviation, meaning "fuckable-on-site". Used to classify extremely sexy people who arouse others to an immediate, uncontrollable frenzy.
by _Jules_ December 21, 2008
Get the FOSmug. fo-fo's are the rims of your car...this originated in the south...when swangin you must have a nice car with nice fo-fo's.
by ~*Nix*~ June 15, 2006
Get the fo-fo'smug. JP: FO!
Me: Did you just tell him to FO?
JP: No I said "oh"
Me: I totally heard "FO" as in "fuck off", sorta like "FU" for "fuck you"
JP: Hahaha
Me: Yeah I couldn't believe you said that at work
Me: This belongs on Urban Dictionary
Me: Did you just tell him to FO?
JP: No I said "oh"
Me: I totally heard "FO" as in "fuck off", sorta like "FU" for "fuck you"
JP: Hahaha
Me: Yeah I couldn't believe you said that at work
Me: This belongs on Urban Dictionary
by randomness323423 February 19, 2011
Get the FOmug. 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)
• 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.
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.
by Night.ER.Ninja July 27, 2014
Get the FOSmug.