Πήγασος Πήγᾰσος, Doric Πάγασος, ὁ, Pegasus, a horse sprung from the blood of Medusa, and named from the springs (πηγαί) of Ocean, near which she was killed, ridden by Bellerophon when he slew Chimaera, Hes.: later poets describe him as winged, Ar.: later still, he was the favourite of the Muses, under whose hoof the fountain Hippocrene (ἵππου κρήνη) sprang up on Helicon, Strab., etc.