Breadcrumb Home > Thesaurus > O Synonyms of operculum Find synonyms for: Noun1. operculum, plateusage: a hard flap serving as a cover for (a) the gill slits in fishes or (b) the opening of the shell in certain gastropods when the body is retractedWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of operculum (Dictionary) ✖ Related Content Daily Word Quiz: porcine Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language