/ Thesaurus / S Synonyms of southwestern united states Find synonyms for: Noun1. Southwest, southwestern United Statesusage: the southwestern region of the United States generally including New Mexico, Arizona, Texas, Nevada, California, and sometimes Utah and ColoradoWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: leonine Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language