4. (Math.) The symbol that expresses the operation to be performed; — called also facient.
Operatory
(Op"er*a*to*ry) n. A laboratory. [Obs.]
Opercle
(O"per*cle) n. [Cf.F. opercule. See Operculum.]
1. (Anat.) Any one of the bony plates which support the gill covers of fishes; an opercular bone.
2. (Zoöl.) An operculum.
Opercula
(O*per"cu*la) n. pl. See Operculum.
Opercular
(O*per"cu*lar) a. Of, pertaining to, or like, an operculum.
Opercular
(O*per"cu*lar), n. (Anat.) The principal opercular bone or operculum of fishes.
Operculate
(O*per"cu*late O*per"cu*la`ted) a. [L. operculatus, p. p. of operculare to furnish with a lid,
fr. operculum lid.]
1. (Bot.) Closed by a lid or cover, as the capsules of the mosses.
2. (Zoöl.) Having an operculum, or an apparatus for protecting the gills; — said of shells and of fishes.
Operculiferous
(O*per`cu*lif"er*ous) a. [Operculum + -ferous.] (Zoöl.) Bearing an operculum.
Operculiform
(O*per"cu*li*form) a. [L. operculum a cover + -form: cf. F. operculiforme.] Having the
form of a lid or cover.
Operculigenous
(O*per`cu*lig`e*nous) a. [Operculum + -genous.] (Zoöl.) Producing an operculum; —
said of the foot, or part of the foot, of certain mollusks.
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.
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.
3. (Zoöl.) (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.
Operetta
(Op`er*et"ta) n. [It., dim. of opera.] (Mus.) A short, light, musical drama.
Operose
(Op"er*ose`) a. [L. operosus, fr. opera pains, labor, opus, operis, work, labor.] Wrought
with labor; requiring labor; hence, tedious; wearisome. "Operose proceeding." Burke. "A very operose
calculation." De Quincey. — Op"er*ose`ly, adv. — Op"er*ose`ness, n.
Operosity
(Op`er*os"i*ty) n. [L. operositas.] Laboriousness. [R.] Bp. Hall.
Operous
(Op"er*ous) a. Operose. [Obs.] Holder. — Op"er*ous*ly, adv. [Obs.]
Opertaneous
(Op`er*ta"ne*ous) a. [L. opertaneus; operire to hide.] Concealed; private. [R.]
Opetide
(Ope"tide`) n. [Ope + tide.] Open time; — applied to different things: (a) The early spring,
or the time when flowers begin opening. [Archaic] Nares. (b) The time between Epiphany and Ash
