c. 1300, "pertaining to the rear, back, posterior," perhaps a back-formation from Old English behindan "back, behind," used as adverb and preposition (see behind), or from or influenced by Old English hindan (adv.) "from behind," from Proto-Germanic *hind- "behind" (cognate with Gothic hindan (prep.) "on that side of, beyond, behind;" German hinten "behind"), of unknown origin. Possibly influenced by Middle English hiner (adv.) "back, rear."