/ Thesaurus / R Synonyms of rio bravo Find synonyms for: Noun1. Rio Grande, Rio Bravousage: a North American river; boundary between the United States and Mexico; flows into Gulf of MexicoWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language