/ Thesaurus / S Synonyms of steam engine Find synonyms for: Noun1. steam engine, external-combustion engineusage: external-combustion engine in which heat is used to raise steam which either turns a turbine or forces a piston to move up and down in a cylinderWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: denizen Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language