Middle English furwe, forowe, forgh, furch, from Old English furh "furrow, trench in the earth made by a plow," from Proto-Germanic *furkh- (source also of Old Frisian furch "furrow;" Middle Dutch vore, Dutch voor; German Furche "furrow;" Old Norse for "furrow, drainage ditch"), from PIE *perk- (2) "to dig, tear out" (source also of Latin porca "ridge between two furrows," Old Irish -rech, Welsh rhych "furrow"). General meaning "narrow trench or channel" is from early 14c. In reference to a deep wrinkle on the face, by 1580s.