A half oviparous, or an oviparous, mammal; a marsupial or monotreme.

The part of the oviduct of certain trematode worms in which the ova are completed and furnished with a shell.

To cause to ooze.

leaking out slowly.

Same as Acrita.

Miry; containing soft mud; resembling ooze; as, the oozy bed of a river.

To darken; to cloud.

The state of being opaque; the quality of a body which renders it impervious to the rays of light; want of transparency; opaqueness.

Opaque.

Opaque.

A large oceanic fish (Lampris guttatus), inhabiting the Atlantic Ocean. It is remarkable for its brilliant colors, which are red, green, and blue, with tints of purple and gold, covered with round silvery spots. Called also king of the herrings.

See Opaque.

A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity.

To give forth a play of colors, like the opal.

A reflection of a milky or pearly light from the interior of a mineral, as in the moonstone; the state or quality of being opalescent.

Reflecting a milky or pearly light from the interior; having an opaline play of colors.

An opaline variety of yellow chalcedony.

To convert into opal, or a substance like opal.

A picture taken on /milky/ glass.

That which is opaque; opacity.

The state or quality of being impervious to light; opacity.

To open.

An instrument, consisting of a tube having one end open and the other end covered with a thin flexible membrance to the center of which is attached a small mirror. It is used for exhibiting upon a screen, by means of rays reflected from the mirror, the vibratory motions caused by sounds produced at the open end of the tube, as by speaking or singing into it.

A bright-colored European actinian (Anemonia sulcata, syn. Anthea sulcata); -- so called because it does not retract its tentacles.

To unclose; to form a hole, breach, or gap; to be unclosed; to be parted.

Taking place in the open air; outdoor; as, an open-air game or meeting.

not cyclic; having no rings of atoms within the molecular structure; having an open chain structure. Opposite of cyclic.

not buttoned at the neck; -- of a shirt; as, dressed casually in shorts and an open-collared shirt.

allowing for a spontaneous response; as, an open-ended question. Contrasted to multiple-choice.

With eyes widely open; alert to possible danger; watchful; vigilant.

Generous; liberal; munificent.

Bareheaded.

Candid; frank; generous.

Ready to entertain new ideas. Contrasted with closed-minded.

Having the mouth open; gaping; hence, greedy; clamorous.

A bird of the genus Anastomus, allied to the stork; -- so called because the two parts of the bill touch only at the base and tip. One species inhabits India, another Africa. Called also open-beak. See Illust. (m), under Beak.

same as opencut.

worked from the exposed surface; -- of mines and mining; as, opencut mining.

having the covering skin pulled back; -- used of mouth or eyes; as, his mouth slightly opened. Opposite of closed.

One who, or that which, opens.

The act or process of opening; a beginning; commencement; first appearance; as, the opening of a speech.

In an open manner; publicly; not in private; without secrecy.

The quality or state of being open.

Anything so constructed or manufactured (in needlework, carpentry, metal work, etc.) as to show openings through its substance; work that is perforated or pierced.

A large African forest tree (Nauclea diderrichii) yielding a strong hard yellow to golden brown lumber; sometimes placed in genus Sarcocephalus, and then called Sarcocephalus diderrichii.

A drama, either tragic or comic, of which music forms an essential part; a drama wholly or mostly sung, consisting of recitative, arias, choruses, duets, trios, etc., with orchestral accompaniment, preludes, and interludes, together with appropriate costumes, scenery, and action; a lyric drama.

Practicable.

An instrument or machine for measuring work done, especially for ascertaining the number of rotations made by a machine or wheel in manufacturing cloth; a counter.

The act of operating or working; operation.

The symbol, quantity, or thing upon which a mathematical operation is performed; -- called also faciend.

Operative. An operative person or thing.

A process for causing animals to behave in a specific manner by rewarding or punishing the animal each time it performs a certain act; after a time, the animal comes to associate the reward or punishment with the act, and will increase or decrease the frequency of performing that act.

To produce, as an effect; to cause.

Of or pertaining to the opera or to operas; characteristic of, suitable for, or resembling, the opera; as, an operatic voice.

pr. p. of operate; as, the operating conditions of the oxidation pond.

The act or process of operating; agency; the exertion of power, physical, mechanical, or moral.

of or pertaining to operations; as, operational procedure.

the doctrine that the meaning of a proposition consists of the operations involved in defining, proving, or applying it.

Of or pertaining to operationalism.

financial transactions at a brokerage; having to do with the execution of trades and keeping customer records.

In an operative manner.

One who, or that which, operates or produces an effect.

A laboratory.

Any one of the bony plates which support the gill covers of fishes; an opercular bone.

See Operculum.

The principal opercular bone or operculum of fishes.

Closed by a lid or cover, as the capsules of the mosses.

Bearing an operculum.

Having the form of a lid or cover.

Producing an operculum; -- said of the foot, or part of the foot, of certain mollusks.

The lid of a pitcherform leaf. The lid of the urnlike capsule of mosses.

A short, light, musical drama.

Wrought with labor; requiring labor; hence, tedious; wearisome.

Laboriousness.

Operose.

Concealed; private.

Open time; -- applied to different things The early spring, or the time when flowers begin opening. The time between Epiphany and Ash Wednesday wherein marriages were formerly solemnized publicly in churches. The time after harvest when the common fields are open to all kinds of stock.

Of, pertaining to, or designating, a substance (called ophelic acid) extracted from a plant (Ophelia) of the Gentian family as a bitter yellowish sirup, used in India as a febrifuge and tonic.

A large brass wind instrument, formerly used in the orchestra and in military bands, having a loud tone, deep pitch, and a compass of three octaves; -- now generally supplanted by bass and contrabass tubas. It developed from the older wooden instrument called the serpent.

The suborder of reptiles which includes the serpents; called also Serpentes.

Of or pertaining to the Ophidia; belonging to serpents.

Of or pertaining to the Ophidiidae, a family of fishes which includes many slender species. One of the Ophidiidae.

The typical genus of ophidioid fishes. [Written also Ophidium.] See Illust. under Ophidioid.

Ophidian.

A natural family of fishes closely related to greenlings (fish of the genus Hexagrammos).

A natural family of succulent ferns cosmopolitan in distribution.

An order coextensive with the family Ophioglossaceae.

The worship of serpents.

Of or pertaining to ophiology.

One versed in the natural history of serpents.

That part of natural history which treats of the ophidians, or serpents.

Divination by serpents, as by their manner of eating, or by their coils.

An order of tailless amphibians having a slender, wormlike body with regular annulations, and usually with minute scales imbedded in the skin. The limbs are rudimentary or lacking. It includes the caecilians. Called also Gymnophiona and Ophidobatrachia.

An ammonite.

Having the form of a serpent.

Feeding on serpents; -- said of certain birds and reptiles.

A genus of venomous East Indian snakes, which feed on other snakes. Ophiophagus elaps is said to be the largest and most deadly of poisonous snakes.

Doctrines and rites of the Ophites.

A mamber of a Gnostic serpent-worshiping sect of the second century.

A constellation in the Northern Hemisphere, delineated as a man holding a serpent in his hands; -- called also Serpentarius.

A genus of ophiurioid starfishes.

Of or pertaining to the Ophiurioidea. One of the Ophiurioidea.

Same as Ophiurioid.

Same as Ophiurioidea.

Of or pertaining to the Ophiurioidea. One of the Ophiurioidea.

A class of star-shaped echinoderms having a disklike body, with slender, articulated arms, which are not grooved beneath and are often very fragile; -- called also Ophiuroida and Ophiuridea. See Illust. under Brittle star.

The supraorbital point.

An inflammation of the membranes or coats of the eye or of the eyeball.

Of, pertaining to, or in the region of, the eye; ocular; as the ophthalmic, or orbitonasal, nerve, a division of the trigeminal, which gives branches to the lachrymal gland, eyelids, nose, and forehead.

An eyestalk; the organ which bears the compound eyes of decapod Crustacea.

severe conjunctivitis; ophthalmia.

Of or pertaining to ophthalmology.

One skilled in ophthalmology; an oculist.

The science which treats of the structure, functions, and diseases of the eye.

An instrument devised by Helmholtz for measuring the size of a reflected image on the convex surface of the cornea and lens of the eye, by which their curvature can be ascertained.

An instrument for viewing the interior of the eye, particularly the retina. Light is thrown into the eye by a mirror (usually concave) and the interior is then examined with or without the aid of a lens.

A branch of physiognomy which deduces the knowledge of a person's temper and character from the appearance of the eyes.

Same as Ophthalmia.

Of, pertaining to, or designating, an organic acid obtained by the oxidation of narcotine.

An alkaloid (C22H23NO7) found in small quantity in opium. It is identical with narcotine. It is present in amounts up to 11% in Papaver somniferum, and is used clinically as an antitussive.