- (n.) The lid of the urnlike capsule of mosses.
- (n.) The lid of a pitcherform leaf.
- (n.) The lid closing the aperture of various species of shells, as the common whelk. See Illust. of Gastropoda.
- (n.) Any lidlike or operculiform process or part; as, the opercula of a dental follicle.
- (n.) Any lid-shaped structure closing the aperture of a tube or shell.
- (n.) The principal opercular bone in the upper and posterior part of the gill cover.
- (n.) The fold of integument, usually supported by bony plates, which protects the gills of most fishes and some amphibians; the gill cover; the gill lid.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). operculum. Retrieved September 21, 2026, from http://smartdefine.org/operculum/definitions/2039001 |
| Chicago | Webster's. 2011. "operculum" http://smartdefine.org/operculum/definitions/2039001 (accessed September 21, 2026). |
| Harvard | Webster's 2011, operculum, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/operculum/definitions/2039001>. |
| MLA | Webster's. "operculum" 27 May 2011. Web. 21 September 2026. <http://smartdefine.org/operculum/definitions/2039001> |