Breadcrumb Home > Thesaurus > R Synonyms of rainbow Find synonyms for: Noun 1. rainbow, bow, arc usage: an arc of colored light in the sky caused by refraction of the sun's rays by rain 2. rainbow, promise, hope usage: an illusory hope; "chasing rainbows" WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of rainbow (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: cognoscenti Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language