Fuck On Sight. An acronym used by two friends to describe a person who they see who they would like to instantly fornicate with on sight.
Two guys are walking when they see a really hot gurl and one gay says to another FOS? And the other gentleman nods in unison.
by Ilovecurry April 14, 2010
Get the FOSmug. Word used to describe a person that quiet often doesnt tell the truth, or in other words is "full of shit"
Also known as a "Fossi"
Also known as a "Fossi"
by J!M! June 27, 2008
Get the FOSmug. TWO definitions:
1) Da numba '4'.
2) Used ta indicate da object, aim, or purpose of an action or activity:
1) Da numba '4'.
2) Used ta indicate da object, aim, or purpose of an action or activity:
by D Dizzle My Nizzle December 23, 2003
Get the fomug. this is a shorter term for "Flap Of Skin". a flap of skin is someone in your group of friends whom you may consider the "loser" or the person who you only hang around with for a certain reason, that reason not perticulary meaning you enjoy their company.
it could also mean someone with NO private parts.
it could also mean someone with NO private parts.
" Kris has no vagina"
"She is but a Flap Of Skin!"
"I couldn't concentrate when the FOS was talking to me, she annoys me to much."
"She is but a Flap Of Skin!"
"I couldn't concentrate when the FOS was talking to me, she annoys me to much."
by i heart flap of skin July 12, 2009
Get the FOSmug. Might that we could have to leave this general vicinity and retreat southward till the coming fo dawn.
by Troy February 5, 2003
Get the fomug. 
Nathan Fillion created the acronym FO, which is the short form for his phrase Full On. It can be used on its own, and/or to intensify a phrase, such as Double Rainbow.
It means that which is:
•fully ecstatically wondrous
•beyond joyfully amazing
•intensely orgasmically blissful
It means that which is:
•fully ecstatically wondrous
•beyond joyfully amazing
•intensely orgasmically blissful
Here are some usage examples for FO, which is short for Full On. (For more examples, see the Twitter page belonging to NathanFillion:)
Nathan Fillion, on his Twitter page, kindly acknowledged my entry work defining his recommendation of the new "in" phrase: "Double Rainbow" on Urban Dictionary! He said it is "Full on." Thank you, Nathan. You are so Full On Double Rainbow! (FO DR!)
The TV shows Castle and Firefly are so intense, they are Full On Double Rainbow! (FO DR!)
Serenity, the feature film starring Nathan Fillion, is so vivid, it's Full On Double Rainbow! (FO DR!)
Nathan Fillion is so awesomely spectacular, sexyhotmessgorgeous, and brilliantly talented, his fame is sweeping across the nation, and over all the world! He is Nathan "Full On" Fillion!
Nathan Fillion, on his Twitter page, kindly acknowledged my entry work defining his recommendation of the new "in" phrase: "Double Rainbow" on Urban Dictionary! He said it is "Full on." Thank you, Nathan. You are so Full On Double Rainbow! (FO DR!)
The TV shows Castle and Firefly are so intense, they are Full On Double Rainbow! (FO DR!)
Serenity, the feature film starring Nathan Fillion, is so vivid, it's Full On Double Rainbow! (FO DR!)
Nathan Fillion is so awesomely spectacular, sexyhotmessgorgeous, and brilliantly talented, his fame is sweeping across the nation, and over all the world! He is Nathan "Full On" Fillion!
by Kcat10 August 1, 2010
Get the FOmug.