1. [proper noun] A taxonomic genus within the family Pegasidae ? small fish with pectoral fins and body covered with hard, bony plates, from the East Indies and China.
2. [proper noun] (Greek mythology) A winged horse fabled to have sprung from the blood of Medusa when she was slain. He is noted for causing, with a blow of his hoof, Hippocrene, the inspiring fountain of the Muses, to spring from Mount Helicon. Bellerophon tamed and rode upon Pegasus when he defeated the Chimaera.
3. [proper noun] (constellation) An autumn constellation of the northern sky, near the vernal equinoctial point, said to resemble the mythical horse. Its three brightest stars, with the brightest star of Andromeda, form the square of Pegasus. It contains the stars Markab and Algenib.
