- The lid of a pitcherform leaf. - The lid of the urnlike capsule of mosses. - Any lidlike or operculiform process or part; as, the
opercula of a dental follicle. - 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. - The principal opercular bone in the upper and posterior
part of the gill cover. - The lid closing the aperture of various species of
shells, as the common whelk. See Illust. of Gastropoda. - Any lid-shaped structure closing the aperture of a tube
or shell.
Definition
[ n.]