/ Thesaurus / S Synonyms of steam boiler Find synonyms for: Noun1. boiler, steam boiler, vesselusage: sealed vessel where water is converted to steamWordNet 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