Although not widely accepted in linguistics, the term preverb's used in Caucasian (including all three families: Northwest Caucasian, Northeast Caucasian and Kartvelian), Caddoan, Athabaskan, and Algonquian linguistics to describe certain elements prefixed to verbs. Theoretically, any prefix could be called a preverbal element. However, in practice, the term preverb applies more narrowly in these families, and refers to a prefixed element that's normally outside the premise of verbal morphology,… (More on Preverb)