/ Thesaurus / L Synonyms of little missouri river Find synonyms for: Noun1. Little Missouri, Little Missouri Riverusage: a river that rises in northeastern Wyoming and flows through Montana and South Dakota to join the Missouri River in North DakotaWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: tenacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language