- Opercula
- Operculum O*per"cu*lum, n.; pl. L. {Opercula}, E.
{Operculums}. [L., a cover or lid, fr. operire to cover.]
1. (Bot.)
(a) The lid of a pitcherform leaf.
(b) The lid of the urnlike capsule of mosses.
[1913 Webster]
2. (Anat.) (a) Any lidlike or operculiform process or part; as, the opercula of a dental follicle. (b) 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. (c) The principal opercular bone in the upper and posterior part of the gill cover. [1913 Webster]
3. (Zo["o]l.) (a) The lid closing the aperture of various species of shells, as the common whelk. See Illust. of {Gastropoda}. (b) Any lid-shaped structure closing the aperture of a tube or shell. [1913 Webster]
The Collaborative International Dictionary of English. 2000.