Definitions by mizJD

F.O.S. 

Short for "Full Of Shitness"

A serious condition in which a person chooses a malady to be a victim of. This malady is usually vague, chronic and untreatable such as a "bad knee."

F.O.S. will tend to flare up when the person is confronted with a situation they would rather avoid.

"Is Robbie coming to your birthday party today?"

"No, she texted me yesterday. Apparently her F.O.S. is acting up, making it impossible for her to walk on her bad knee."

F.O.S. by mizJD January 10, 2010