Index of English words, starting with "op"

(1) - Operator (n.) The symbol that expresses the operation to be performed; -- called also facient.
(2) - Operator (n.) A dealer in stocks or any commodity for speculative purposes; a speculator.
(3) - Operator (n.) One who performs some act upon the human body by means of the hand, or with instruments.
(4) - Operator (n.) One who, or that which, operates or produces an effect.

(1) - Opercular (n.) The principal opercular bone or operculum of fishes.

(1) - Operculum (n.) Any lid-shaped structure closing the aperture of a tube or shell.
(2) - Operculum (n.) The lid closing the aperture of various species of shells, as the common whelk. See Illust. of Gastropoda.
(3) - Operculum (n.) The principal opercular bone in the upper and posterior part of the gill cover.
(4) - Operculum (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.
(5) - Operculum (n.) Any lidlike or operculiform process or part; as, the opercula of a dental follicle.
(6) - Operculum (n.) The lid of the urnlike capsule of mosses.
(7) - Operculum (n.) The lid of a pitcherform leaf.