An order of extinct flying reptiles; -- called also Pterosauria.

A group of extinct Reptilia, intermediate in structure (especially with regard to the pelvis) between reptiles and birds.

Observation of birds and their habits.

Of or pertaining to ornithotomy.

One who is skilled in ornithotomy.

The anatomy or dissection of birds.

A machine for use in making topographical maps. It is operated by being pushed across country, and not only records distances, like the perambulator, but also elevations.

Of or pertaining to orography.

That branch of science which treats of mountains and mountain systems; orology; as, the orography of Western Europe.

A camera for obtaining a circular panoramic view of the horizon. The photographic plate is placed horizontally with a vertical lens above. A mirror of peculiar shape reflects light from the entire horizon to the lens, by means of which it is focused upon the plate.

A genus of American Eocene mammals allied to the horse, but having four toes in front and three behind.

An alloy, chiefly of copper and zinc or tin, resembling gold in color and brilliancy.

Of or pertaining to orology.

One versed in orology.

The science or description of mountains.

An aneroid barometer having a second scale that gives the approximate elevation above sea level of the place where the observation is made.

Characterized by fullness, clearness, strength, and smoothness; ringing and musical; -- said of the voice or manner of utterance. The orotund voice or utterance

The orotund mode of intonation.

See Orpheline.

To cause to become an orphan; to deprive of parents.

The state of being an orphan; orphanhood; orphans, collectively.

Orphanhood.

A little orphan.

The state or condition of being an orphan; orphanage.

Orphanhood.

The care and support of orphans.

An old instrument of the lute or cittern kind.

Of or pertaining to Orpheus, the mythic poet and musician; as, Orphean strains.

An orphan.

The famous mythic Thracian poet, son of the Muse Calliope, and husband of Eurydice. He is reputed to have had power to entrance beasts and inanimate objects by the music of his lyre.

Pertaining to Orpheus; Orphean; as, Orphic hymns.

A band of rich embroidery, wholly or in part of gold, affixed to vestments, especially those of ecclesiastics.

Arsenic sesquisulphide, produced artificially as an amorphous lemon-yellow powder, and occurring naturally as a yellow crystalline mineral; -- formerly called auripigment. It is used in king's yellow, in white Indian fire, and in certain technical processes, as indigo printing.

A yellow pigment of various degrees of intensity, approaching also to red.

A low plant with fleshy leaves (Sedum telephium), having clusters of purple flowers. It is found on dry, sandy places, and on old walls, in England, and has become naturalized in America. Called also stonecrop, and live-forever.

See Orach.

An apparatus which illustrates, by the revolution of balls moved by wheelwork, the relative size, periodic motions, positions, orbits, etc., of bodies in the solar system.

A sort of gold or silver lace.

Leaf metal of bronze; Dutch metal. See under Dutch.

See Archil.

Pertaining to, or designating, an acid found in certain lichens, and called also lecanoric acid.

Pertaining to, or designating, an organic acid obtained by a partial decomposition of orsellic acid as a white crystalline substance, and related to protocatechuic acid.

A morsel left at a meal; a fragment; refuse; -- commonly used in the plural.

Any one of numerous small two-winged flies of the family Ortalidae. The larvae of many of these flies live in fruit; those of others produce galls on various plants.

A brachiopod shell of the genus Orthis, and allied genera, of the family Orthidae.

An extinct genus of Brachiopoda, abundant in the Paleozoic rocks.

A variety of allanite occurring in slender prismatic crystals.

Designating a complex ether, C.(OC2H5)4, which is obtained as a liquid of a pleasant ethereal odor by means of chlorpicrin, and is believed to be a derivative of the hypothetical normal carbonic acid, C.(OH)4.

That point in which the three perpendiculars let fall from the angles of a triangle upon the opposite sides, or the sides produced, mutually intersect.

An extinct genus of Paleozoic Cephalopoda, having a long, straight, conical shell. The interior is divided into numerous chambers by transverse septa.

An orthoceras; also, any fossil shell allied to Orthoceras.

Common or potash feldspar crystallizing in the monoclinic system and having two cleavages at right angles to each other. See Feldspar.

Breaking in directions at right angles to each other; -- said of the monoclinic feldspars.

The diagonal or lateral axis in a monoclinic crystal which is at right angles with the vertical axis.

See the Note under Dome, 4.

The treatment of the teeth so as to make the teeth align properly within the mouth, usually involving the wearing of braces and sometimes oral surgery.

Of or pertaining to orthodontics or orthodontia.

A branch of dentistry specializing in the treatment of the teeth so as to make the teeth align properly within the mouth; it usually involves fitting a patient with braces and sometimes oral surgery.

a dentist specializing in the prevention or correction of irregularities of the teeth; one specializing in orthodontics.

Sound in opinion or doctrine, especially in religious doctrine; hence, holding the Christian faith; believing the doctrines taught in the Scriptures; -- opposed to heretical and heterodox; as, an orthodox Christian.

Orthodoxness.

Orthodoxly.

Orthodox.

Pertaining to, or evincing, orthodoxy; orthodox.

In an orthodox manner; with soundness of faith.

The quality or state of being orthodox; orthodoxy.

Soundness of faith; a belief in the doctrines taught in the Scriptures, or in some established standard of faith; -- opposed to heterodoxy or to heresy.

Of or pertaining to orthodromy.

The art of sailing in a direct course, or on the arc of a great circle, which is the shortest distance between any two points on the surface of the globe; great-circle sailing; orthodromy.

The act or art of sailing on a great circle.

Of or pertaining to orthoepy, or correct pronunciation.

One who is skilled in orthoepy.

The art of uttering words correctly; a correct pronunciation of words; also, mode of pronunciation.

Direct fertilization in plants, as when the pollen fertilizing the ovules comes from the stamens of the same blossom; -- opposed to heterogamy.

Orthognathous.

The quality or state of being orthognathous.

Having the front of the head, or the skull, nearly perpendicular, not retreating backwards above the jaws; -- opposed to prognathous. See Gnathic index, under Gnathic.

A rectangular figure.

Right-angled; rectangular; as, an orthogonal intersection of one curve with another.

Perpendicularly; at right angles; as, a curve cuts a set of curves orthogonally.

An orthographic projection, sometimes partly in section, esp. of a building.

One versed in orthography; one who spells words correctly.

Of or pertaining to orthography, or right spelling; also, correct in spelling; as, orthographical rules; the letter was orthographic.

In an orthographical manner according to the rules of proper spelling according to orthographic projection.

One who spells words correctly; an orthographer.

To spell correctly or according to usage; to correct in regard to spelling.

The right description of things.

Having the axes at right angles to one another; -- said of crystals or crystalline forms.

The art or practice of constructing verses correctly; the laws of correct versification.

Having the right form.

Of, pertaining to, or employed in, orthopedics; relating to the prevention or cure of deformities of children, or, in general, of the human body at any age; as, orthopedic surgery; an orthopedic hospital.

The art or practice of correcting disorders or deformities of the spine and joints, or, by extension, any deformities of the human body.

One who prevents, cures, or remedies deformities, esp. in children.

Same as orthopedics.

The art of correct articulation; voice training.

A name given to the two planes in the monoclinic system which are parallel to the vertical and orthodiagonal axes.

Specifically, a morbid condition in which respiration can be performed only in an erect posture; by extension, any difficulty of breathing.

An orthopedist.

An extinct order of reptiles which stood erect on the hind legs, and resembled birds in the structure of the feet, pelvis, and other parts.

The treatment of deformities in the human body by mechanical appliances.

An order of mandibulate insects including grasshoppers, locusts, cockroaches, mantids, crickets, katydids, etc. See Illust. under Insect.

One of the Orthoptera.

Of or pertaining to the Orthoptera.

Noting the system of crystallization which has three unequal axes at right angles to each other; trimetric. See Crystallization.

An instrument designed to show the condition of the superficial portions of the eye.

Giving an image in correct or normal proportions; giving a flat field of view; as, an orthoscopic eyepiece.

Designating the form of silicic acid having the normal or highest number of hydroxyl groups.

Having the seeds straight, as in the fruits of some umbelliferous plants; -- opposed to coelospermous.

A chiton, or loose, ungirded tunic, falling in straight folds.

A longitudinal rank, or row, of leaves along a stem.

Cutting at right angles.

Having two cleavages at right angles with one another.

The property of cutting at right angles.

Retaining the accent; not enclitic; -- said of certain indefinite pronouns and adverbs when used interrogatively, which, when not so used, are ordinarilly enclitic.

Having the longer axis vertical; -- said of erect stems.

Having the axis of an ovule or seed straight from the hilum and chalaza to the orifice or the micropyle; atropous.

That variety of xylene (C6H4(CH3)2) in which the two methyl groups are in the ortho position; a colorless, liquid, combustible hydrocarbon resembling benzene.

Of or relating to the time or act of rising; eastern; as, the ortive amplitude of a planet.

A European singing bird (Emberiza hortulana), about the size of the lark, with black wings. It is esteemed delicious food when fattened. Called also bunting. In England, the wheatear (Saxicola oenanthe). In America, the sora, or Carolina rail (Porzana Carolina). See Sora.

One of several species of East Indian birds of the genera Ortygis and Hemipodius. They resemble quails, but lack the hind toe. See Turnix.