The arbelas (plural arbelai) was a type of ancient Roman gladiator. The word is a hapax legomenon, occurring only in the Oneirocritica of Artemidorus, a Greek work on dream interpretation that discusses the symbolism of various gladiator types. It may be related to the Greek word arbelos (ἄρβηλος), a cobbler's semicircular blade used to cut leather similar to an ulu.