1) Vehicle modification 
[automobile] Frenching is the act of recessing or moulding a headlight, taillight, antenna or number plate into a car body to give a smoother look to the vehicle. The name originates from the end result looking like a French cuff of a shirt sleeve, which has a ridge at the end. Also known as tunnelling, it is a common modification used on l...
(from the article `malformation`) A common deformity of tobacco, called frenching, occurs in most tobacco-growing regions of the world. The advanced state of this condition is ...
Frenching is American slang for taking leave, time off, without authorisation.
Frenching is the process of removing one and a half inches of meat from the end opposite the loin eye of the roast or rib chops.