/ Thesaurus / M Synonyms of mesohippus Find synonyms for: Noun1. mesohippus, horse, Equus caballususage: North American three-toed Oligocene animal; probably not directly ancestral to modern horsesWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: lyre Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language