/ Thesaurus / M Synonyms of magnesium oxide Find synonyms for: Noun1. periclase, magnesia, magnesium oxide, mineralusage: a white solid mineral that occurs naturally as periclase; a source of magnesiumWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: cosmology Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language