/ Thesaurus / T Synonyms of three year old Find synonyms for: Noun1. three-year-old horse, three year old, racehorse, race horse, bangtailusage: a racehorse that is three years oldAdjective1. three-year-old, young (vs. old), immatureusage: three years of ageWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: cacophony Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language