Exactly what the term implies. It refers to someone who seem to always say the most inappropriate thing at the most inappropriate time.

Commonly also referred to as CFMD. There is no known medical cure for this ailment. It tends to be hereditary and is usually passed down from the father's side of the family. Typically the gene is passed from father to son but it has been known to appear in females. Sufferers of this malady also tend to lack class and moral terpitude especially when surrounded by groups of people. They also tend to tell really inappropriate jokes that includes racist and or sexist comments and wonder why they are still single.
Guy with CFMD: Wow you have nice tits.

Hot chick in bar: OMG! You are crude.

CFMD's Wingman: You can't just say that to a stranger especially some hot chick you have no chance with. You must have Chronic Foot in the Mouth Disease like your daddy.
by activestatic July 15, 2010