Breadcrumb Home > Thesaurus > I Synonyms of io Find synonyms for: Noun 1. Io usage: (Greek mythology) a maiden seduced by Zeus; when Hera was about to discover them together Zeus turned her into a white heifer 2. Io usage: the closest of Jupiter's moons; has active volcanoes WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of io (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Hanukkah Origins of the Christmas Holiday Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 Krampus: The Christmas Devil Kwanzaa ✖ Related Content Daily Word Quiz: jactation Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language