Term to describe when a girl has a noticeable amount of facial hair. It comes from when a person has mustard, ketchup etc. on their face from eating food, and also french girls, since they sometimes do not shave.
Friend 1: Hey how did that blind date go??
Friend 2: Oh, well, she had a nice body and all, shes actually nice, but i noticed some French Mustard.
Friend 1: Ohhh, thats a boner killer. well, she can always shave it off.
Friend 2:True she could shave, but how do i tell her to without being an ass?
Friend 1: I guess you cant, you will just have to deal with the French Mustard.
A dirty practical joke, where a squeeze mustard bottle is shoved into the victim's ass nozzle first and squeezed, ejecting the mustard into said victim's ass. Originated by the infamous John Gagain, coffee potter extraordinaire.
1. When Billy passed out naked after a night of drinking, his friends gave him a Colonel Mustard. Boy was he surprised!