a misspelling of "for" when someone is typing a mile a minute, or in capitalised form, the hypothetical compound of oxygen fluoride
by eszett March 8, 2003
Get the fomug. 1. Furby is FOS
2. Morris: I went for a bit of FOS with apiphonyiernfi
3. Are you going to millys FOS?
2. Morris: I went for a bit of FOS with apiphonyiernfi
3. Are you going to millys FOS?
by jOeFiSh15 January 20, 2009
Get the FOSmug. by Mai327 June 9, 2011
Get the FOSmug. by Donatello Quentinstein Kennedy Ripken Sr. September 20, 2007
Get the Fomug. n. to describe a person who is 'Full Of Shit', and treats those who try to help them with disrespect.
Person 1: 'I'm not coming to my doctor's appointment today because you didn't tell me I had to pay anything.'
Person 2: 'Don't be such a FOS.'
Person 2: 'Don't be such a FOS.'
by Maria Espia March 17, 2008
Get the FOSmug. by Archie Black July 11, 2003
Get the "fo"mug. by MousePad July 25, 2008
Get the fomug.