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. Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 12 Steps to a New Year New Year's Resolution to Slim Down? Martin Luther King Speeches Books of the Bible: Old Testament Books in Order ✖ Related Content Daily Word Quiz: jerrybuilt Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language