Definition:
ios
- ioslarge volcanically active moon of the planet Jupiter
- ioswoman who, being loved by Zeus, was transformed into a white heifer and was, at the wish of Hera, first guarded by Argus and later pursued through the world by a gadfly until she reached Egypt, where she resumed her true shape: identified by the Egyptians
- iosshowy, yellow moth, Automeris io, of North America, having a prominent pink and bluish eyespot on each hind wing
- iossmall hawk, Buteo solitarius, having two plumage phases and occurring only on the island of Hawaii, where it is a rare species and the only living indigenous bird of prey
- iosIO, a cry of joy