Onahole literally means "masturbation hole"; a portmanteau of the Japanese words "onanī" and "hōru", and that's exactly what it is and what it's for. Onaholes are simulated vaginas (or anuses or mouths) for people with penises to masturbate with, and they encourage thrusting to orgasm. Most onaholes have textured canals and some even have a suction chamber. A realistic onahole feels very close to the real thing!