winged horse in Gk. mythology, late 14c., from L., from Gk. Pegasos, usually said to be from pege "spring, font" (pl. pegai), especially in "springs of Ocean," near which Medusa was said to have been killed by Perseus (Pegasus sprang from her blood). But this may be folk etymology, and the suffix -asos suggests a pre-Gk. origin.