/ Thesaurus / I Synonyms of iron horse Find synonyms for: Noun1. iron horse, locomotive, engine, locomotive engine, railway locomotiveusage: (c. 1840) an early term for a locomotiveWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: devout Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language