Ketterweed
Marijuana that is of inferior quality, containing little, if any, THC or cannabanoids; alternatively used to describe any substance that resembles marijuana but is actually a different (non-psychoactive) herb. Use of the term appears to be restricted to central Ohio, Baltimore, MD and the Cleveland-Buffalo-Rochester corridor.
Mom, Toss me your car keys. My dealer sold me some ketterweed and I'm gonna drive over there and burn down his f-ing house.