An instrument for measuring the limits of distinct vision in different individuals, and thus determiming the proper focal length of a lens for correcting imperfect sight.

A catering; a buying of provisions.

That may be chosen; desirable.

To choose; to wish for; to desire.

The act of optating; a wish.

Something to be desired.

In an optative manner; with the expression of desire.

The organ of sight; an eye.

the ability of a chemical compound to rotate the plane of plane-polarized light. This is found only in chemicals whose molecular structure does not have a plane of symmetry, and is common in biochemical compounds.

a cable containing multiple optical fibers.

A thin fiber of very pure glass used to carry signals transmitted by means of light. It has much greater information-carrying capacity than a copper wire, and in the 1990's became a dominant means of transmitting telephone communications over long distances.

Of, pertaining to, or using vision or sight; as, optical illusions.

By optics or sight.

One skilled in optics.

That branch of physical science which treats of the nature and properties of light, the laws of its modification by opaque and transparent bodies, and the phenomena of vision.

A telescope with a diagonal eyepiece, suspended vertically in gimbals by the object end beneath a fixed diagonal plane mirror. It is used for delineating landscapes, by means of a pencil at the eye end which leaves the delineation on paper.

Government by the nobility.

Best possible; most desirable; optimum; as, the optimal concentration of a drug.

Of or pertaining to the nobility or aristocracy. A nobleman or aristocrat; a chief man in a state or city.

The nobility or aristocracy of ancient Rome, as opposed to the populares.

One of those who stand in the second rank of honors, immediately after the wranglers, in the University of Cambridge, England. They are divided into senior and junior optimes.

Same as optimize.

Of or pertaining to optimism; tending, or conforming, to the opinion that all events are ordered for the best.

The state of being best.

To make as useful, effective, or functional as possible; as, to optimize the speed of a computer program.

The most favorable condition, greatest degree, or largest amount possible under given circumstances.

The power of choosing; the right of choice or election; an alternative.

Involving an option; depending on the exercise of an option; left to one's discretion or choice; allowed but not compulsory; as, optional studies; it is optional with you to go or stay. See Elective, n.

In an optional manner.

A person who holds an option to buy or sell a financial instrument. See option.

The cavity of one of the optic lobes of the brain in many animals.

An image of external objects fixed on the retina by the photochemical action of light on the visual purple. See Optography.

The production of an optogram on the retina by the photochemical action of light on the visual purple; the fixation of an image in the eye. The object so photographed shows white on a purple or red background. See Visual purple, under Visual.

An instrument for measuring the distance of distinct vision, mainly for the selection of eveglasses.

One who is skilled in or practices optometry, especially one who examines the eyes for defects in vision and prescribes the proper lenses to correct any defects discovered.

Measurement of the range of vision, esp. by means of the optometer.

Wealth; riches; affluence.

See Opulence.

Having a large estate or property; wealthy; rich; affluent; as, an opulent city; an opulent citizen.

A genus of cactaceous plants; the prickly pear, or Indian fig.

An order of plants coextensive with the family Cactaceae, comprising the cactuses.

A work; a musical composition.

A small or petty work.

An opuscule.

Opium.

A small, handsome trout (Salvelinus oquassa), found in some of the lakes in Maine; -- called also blueback trout.

Yellow or gold color, -- represented in drawing or engraving by small dots.

A money of account among the Anglo-Saxons, valued, in the Domesday Book, at twenty pence sterling.

A South American monkey of the genus Callithrix, esp. Callithrix Moloch.

A genus (Atriplex) of herbs or low shrubs of the Goosefoot family, most of them with a mealy surface.

To utter oracles.

Of or pertaining to an oracle; uttering oracles; forecasting the future; as, an oracular tongue.

Oracular; of the nature of an oracle.

Stormy.

See Orison.

Uttered by the mouth, or in words; spoken, not written; verbal; as, oral traditions; oral testimony; oral law.

Surgery performed within the mouth cavity, especially that performed around the gums and teeth as an expedient for the purpose of preservation or replacement of teeth.

In an oral manner.

See Orang-outang.

An arboreal anthropoid ape (Pongo pygmaeus, formerly Simia satyrus), which inhabits Borneo and Sumatra. Often called simply orang. It is now an endangered species.

A drink made of orange juice and water, corresponding to lemonade; orange sherbet.

Candied orange peel; also, orangeade.

Attachment to the principles of the society of Orangemen; the tenets or practices of the Orangemen.

One of a secret society, organized in the north of Ireland in 1795, the professed objects of which are the defense of the reigning sovereign of Great Britain, the support of the Protestant religion, the maintenance of the laws of the kingdom, etc.; -- so called in honor of William, Prince of Orange, who became William III. of England.

An American ranunculaceous plant (Hidrastis Canadensis), having a yellow tuberous root; -- also called yellowroot, golden seal, etc.

A place for raising oranges; a plantation of orange trees.

Deep orange-yellow; dark yellow.

Of or pertaining to a coast.

To deliver an oration.

A public speaker; one who delivers an oration; especially, one distinguished for his skill and power as a public speaker; one who is eloquent.

Oratorical.

See Fathers of the Oratory, under Oratory.

Of or pertaining to an orator or to oratory; characterized by oratory; rhetorical; becoming to an orator; as, an oratorical triumph; an oratorical essay.

Oratorical.

To play the orator.

The art of an orator; the art of public speaking in an eloquent or effective manner; the exercise of rhetorical skill in oral discourse; eloquence.

A woman who makes public addresses.

A woman plaintiff, or complainant, in equity pleading.

To become round like an orb.

Any spider of the family Araneidae (called also Argiopidae) that spins a web with a pattern of lines spiraling outward from the center. They have eight similar eyes. The golden orb weaver, Mephila clavipes, is known for the remarkable dragline silk it produces for use as a frame for its web and as a line on which it can plummet down and nab prey. This silk has a high tensile strength and is stronger than the toughest current synthetic polymer (Kevlar).

Bereaved; fatherless; childless.

The state of being orbate, or deprived of parents or children; privation, in general; bereavement.

Having the form of an orb; round.

Spherical; orbicular; orblike; circular.

A small orb, or sphere.

Same as Discina.

Resembling or having the form of an orb; spherical; circular; orbiculate.

That which is orbiculate; especially, a solid the vertical section of which is oval, and the horizontal section circular.

Made, or being, in the form of an orb; having a circular, or nearly circular, or a spheroidal, outline.

The state or quality of being orbiculate; orbicularness.

The path described by a heavenly body in its periodical revolution around another body; as, the orbit of Jupiter, of the earth, of the moon.

Of or pertaining to an orbit.

Orbital.

Situated around the orbit; as, the orbitary feathers of a bird.

A division of spiders, including those that make geometrical webs, as the garden spider, or Epeira.

A genus of living Foraminifera, forming broad, thin, circular disks, containing numerous small chambers.

Of or pertaining to the orbit and the nose; as, the orbitonasal, or ophthalmic, nerve.

Of or pertaining to the sphenoid bone and the orbit, or to the orbitosphenoid bone. The orbitosphenoid bone, which is situated in the orbit on either side of the presphenoid. It generally forms a part of the sphenoid in the adult.

Of or pertaining to the orbitosphenoid bone; orbitosphenoid.

Orbital.

Orbation.

A genus of minute living Foraminifera having a globular shell.

Orblike; having the course of an orb; revolving.

Any of several cetaceans, especialy the grampus (Grampus griseus) of the dolphin family.

The killer whale (Orcinus orca).

Of or pertaining to the Orkney Islands.

A reddish brown amorphous dyestuff, C7H7NO3, obtained from orcin, and forming the essential coloring matter of cudbear and archil. It is closely related to litmus.

See Archil.

Same as Alkanet, 2.

A garden.

The cultivation of orchards.

One who cultivates an orchard.

Archil.

A treatise upon dancing.

See Orchestra.

Any species of amphipod crustacean of the genus Orchestia, or family Orchestidae. See Beach flea, under Beach.

The space in a theater between the stage and the audience; -- originally appropriated by the Greeks to the chorus and its evolutions, afterward by the Romans to persons of distinction, and by the moderns to a band of instrumental musicians. Now commonly called orchestra pit, to distinguish it from the section of the main floor occupied by spectators.

Of or pertaining to an orchestra; suitable for, or performed in or by, an orchestra.

to write an orchestra score for; -- of a musical composition.

Arranged for performance by an orchestra; -- of a musical composition.