Ron Imhoff is a nickname for an individual that has had no success in their career, especially athletes, due to drug problems that include meth. This is named after the infamous MMA fighrer Ron "Stinkbug" Imhoff from Davenport, IA that had a foolish 1-16 MMA record and had noted his training included heavy meth and wrestling with Devon.
That guy has no success at all due to his meth problems, he must be a real Ron Imhoff.
Text or instant messenger speak for "In My Humble Opinion, Fuck U!". To be used as a gracious way to tell someone off. Most commonly used when someone is being arrogant or is rubbing something in your face.
"Canada won the Gold in Hockey! In your face!". IMHOFU!!!