among the poets, a horse imagined to have wings; being that on which Bellerophon was fabled to be mounted when he engaged the Chimera. See CHIMERA.

The opening of the fountain Hippocrene on Mount Helicon is ascribed to a blow of Pegasus's hoof. It was supposed to have flown away to heaven, where it became a constellation. Hence

PEGASUS in Astronomy, the name of a constellation of the northern hemisphere, in form of a flying horse. See ASTROLOGY.