Breadcrumb Home > Thesaurus > O Synonyms of operculum Find synonyms for: Noun 1. operculum, plate usage: 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 retracted WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of operculum (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Hanukkah Origins of the Christmas Holiday Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 Krampus: The Christmas Devil Kwanzaa ✖ Related Content Daily Word Quiz: tintinnabulation Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language