/ Thesaurus / B Synonyms of black opal Find synonyms for: Noun1. black opal, opalusage: a dark colored opal with internal reflections of green or redWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: sumptuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language