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Medical Dictionary


odorimetry (o′do-rim′e-tre)
The determination of the comparative power of different substances in stimulating olfactory sensations. [odor + G. metron, measure]

odorivection (o′dor-i-vek′shun)
Conveying or bearing an odor, as in the air. [odor + L. vector, a carrier]

odorography (o′do-rog′ra-fe)
Description of odors. [odor + G. graphe, a description]

odorous (o′dor-us)
SYN: odoriferous.

Joseph P., U.S. physician, 1841–1898. See O. tube.

odyn-, odyno-
Pain. [G. odyne]

odynacusis (o-din′a-koo′sis)
Hypersensitiveness of the organ of hearing, so that sounds cause actual pain. [odyn- + G. akouo, to hear]

odynophagia (o-din-o-fa′je-a)
Pain on swallowing. [odyno- + G. phago to eat]

odynophonia (o-din-o-fo′ne-a)
Pain on using the voice. [odyno- + G. phone, sound, voice]

Symbol for oersted.

For words so beginning and not found here, see e-.

oedipism (ed′i-pizm)
1. Manifestation of the Oedipus complex. 2. Rarely used term for self-infliction of injury to the eyes, usually an attempt at evulsion. [Oedipus, G. myth. char.]

Eusebio, Italian anatomist, 1827–1903. See O. muscles, under muscle.

oenanthal (e-nan′thal)
SYN: heptanal.

oersted (Oe) (er′sted)
A unit of magnetic field intensity; the magnetic field intensity that exerts a force of 1 dyne on a unit magnetic pole; equal to (1000/4π) A m−1. [Hans-Christian O., Danish physicist, 1777–1851]

oesophagostomiasis ( e-sof′a-go-sto-mi′a-sis)
Infection with nematode parasites of the genus Oesophagostomum. SYN: esophagostomiasis. [G. oi-sophagos, gullet (esophagus), + stoma, mouth, + -iasis, condition]

Oesophagostomum (e-sof-a-gos′to-mum)
A genus of strongyle nematodes (subfamily Oesophagostominae) that encyst in the intestinal wall of herbivores and primates, causing nodular disease. Larvae appear to stimulate a host reaction in the intestinal wall, forming nodules in which the worms complete their development (unless the host is immune); they then leave the nodule and feed as adults in the lumen of the large intestine. [G. oisophagos, gullet (esophagus), + stoma, mouth] O. apiostomum a nematode species that has been reported in northern Nigeria and central Africa to encyst under the submucosa of the human intestine and occasionally cause dysentery; a common parasite of monkeys and apes, both in captivity and in the wild. O. brevicaudum a nematode species that occurs in the cecum and colon of pigs in North America and India. O. brumpti a nematode species described from African monkeys and reported occasionally in humans. O. columbianum a nematode species that occurs in sheep, goats, and wild African antelopes; except when present in large numbers, it does not appear to seriously affect the health of the host. O. dentatum a nematode species that affects the colon of swine; the lesions are similar to those in sheep. O. georgianum a nematode species that occurs in the cecum and colon of pigs in the U.S. O. quadrispinulatum a species that occurs in the cecum and colon of pigs in the Americas, Europe, and Southeast Asia. O. radiatum a species that occurs worldwide in cattle and water buffalo; the lesions are similar to those of sheep. O. stephanostomum a species of nematode occurring in chimpanzees, monkeys, and gorillas in Africa, but also reported from humans and monkeys in Brazil. O. venulosum a species that occurs worldwide in the cecum and colon of cattle, sheep, goats, deer, and many other ruminants.

oestradiol (es-tra-di′ol)
SYN: estradiol.

oestrids (est′ridz)
Common name for botflies of the family Oestridae, such as Oestrus. [G. oistros, gadfly]

oestriol (es′tre-ol)
SYN: estriol.

oestrogen (es′tro-jen)
SYN: estrogen.

oestrone (es′tron)
SYN: estrone.

oestrosis (es-tro′sis)
Infection of small ruminants and, rarely, humans with larvae of the fly Oestrus ovis.

Oestrus (es′tus)
A genus of tissue-invading flies that cause myiasis in sheep; the head botflies in the family Oestridae. O. ovis (a nose fly) is a grayish brown, robust, hairy, beelike botfly, imported from Europe, and now a serious pest in parts of the U.S.; larvae are deposited by the adult fly in the nostrils of sheep, and inch-long larvae develop in the paranasal sinuses, causing considerable mucous discharge and distress in old or weak sheep. [G. oistros, gadfly]

official (o-fish′al)
Authoritative; denoting a drug or a chemical or pharmaceutical preparation recognized as standard in the pharmacopeia. Cf.:officinal. [L. officialis, fr. officium, a favor, service, fr. opus, work, + facio, to do]

officinal (o-fis′i-nal)
Denoting a chemical or pharmaceutical preparation kept in stock, in contrast to magistral (prepared extemporaneously according to a physician's prescription); an o. preparation is often, though not necessarily, official. [L. officina, shop]

Kyusaka, 20th century Japanese physician. See O.-Knaus rule.

Sir Alexander, Scottish surgeon, 1844–1929. See O. line, O.-Luc operation.

Chita, Japanese ophthalmologist, 1875–1945. See O. disease.

Joseph H., U.S. otolaryngologist, 1915–1983. See O. operation.

Michael, Jr., U.S. surgeon, 1869–1926. See O. forceps.

Abbreviation for Oral Hygiene Index.

Abbreviation for Simplified Oral Hygiene Index.

Georg S., German physicist, 1787–1854. See o., O. law.

ohm (Ω) (om)
The practical unit of electrical resistance; the resistance of any conductor allowing 1 A of current to pass under the electromotive force of 1 V. [G.S. O.]

ohmammeter (om-am′e-ter)
A combined ohmmeter and ammeter.

ohmmeter (om′e-ter)
An instrument for determining the resistance, in ohms, of a conductor.

ohne Hauch (o′na howch)
Term used to designate the nonspreading growth of nonflagellated bacteria on agar media; also applied to somatic agglutination. SEE ALSO: O antigen. [Ger. without breath]

Ohngren line
See under line.

Abbreviation for osteogenesis imperfecta.

For words so beginning and not found here, see e-.

Resemblance to, equivalent to Eng. -form. [G. eidos, form, resemblance]

oidia (o-id′ea)
Plural of oidium.

oidium, pl .oidia (o-id′e-um, o-id′e-a)
Formerly used term for arthroconidium. [Mod. L. dim. of G. oon, egg]

oil (oyl)
An inflammable liquid, of fatty consistency and unctuous feel, which is insoluble in water, soluble or insoluble in alcohol, and freely soluble in ether. Oils are variously classified as animal, vegetable, and mineral oils according to their source (the mineral oils probably being of remote animal and vegetable origin); into fatty (fixed) and volatile oils; and into drying and nondrying (fatty) oils, the former becoming gradually thicker when exposed to the air and finally drying to a varnish, the latter not drying but liable to become rancid on exposure. Many of the oils, both fixed and volatile, are used in medicine. For individual oils, see the specific names. [L. oleum; G. elaion, originally olive o.] absolute oils essential oils that are obtained by the removal of insoluble compounds from concrete oils. o. of American wormseed SYN: o. of chenopodium. o. of anise volatile o. derived from the dried ripe fruit of Pimpinella anisum (family Umbelliferae) or of Illicium verum, (family Magnoliaceae) (Chinese star anise); has a characteristic anise aroma, resembling fennel. Used in manufacture of liqueurs, and as flavoring for candies, cookies, dentifrices. Pharmaceutical aid (flavor). Carminative. o. of bay volatile o. derived by steam distillation of the dried leaves of Pimenta (Myrcia) acris (family Myrtaceae); o. of myrcia; used as an aromatic in the manufacture of bay rum and as a pharmaceutical aid. o. of bergamot volatile o. derived by steam distillation from the rind of the fresh fruit of Citrus aurantium or C. bergamia; contains l-linalyl acetate, l-linalool; d-limonene, dipentene, bergaptene; used as a deodorant in preparations containing malodorous ingredients and as an aromatic in perfumes, hairdressings, and pomades. betula o. o. of sweet birch, a volatile o. obtained by distillation from the bark of Betula lenta (sweet birch); used as a flavoring agent and as a counterirritant liniment. SEE ALSO: methyl salicylate. o. of bitter almond volatile o. from the dried ripe kernels of bitter almonds or from other kernels containing amygdalin, such as apricots, peaches, plums, and cherries; obtained by steam distillation subsequent to maceration of the source with water. Formerly used as an antipruritic; poisonous—releases hydrocyanic acid (hydrogen cyanide). Only the o. free of hydrogen cyanide may be used to flavor liquors and foods. o. of bitter orange volatile o. obtained by steam distillation from the fresh peel of Citrus aurantium (family Rutaceae). Aromatic material used as a flavoring agent in pharmaceuticals and foods and liquors; also used in perfumes. o. of cardamom volatile o. obtained by steam distillation from the seeds of Elettaria cardamomum (family Zingiberacea.) A flavoring agent in pharmaceuticals (syrups), liquors, sauces, confections, and baked goods; formerly used as a carminative. o. of chenopodium volatile o. from the fresh above-ground part of the flower American wormseed, Chenopodium ambrosioides, or C. anthelminticum. Used as an anthelmintic. SYN: o. of American wormseed. o. of cherry laurel volatile o. derived by steam distillation from Prunus laurocerasus (family Rosaceae); similar to o. of bitter almond; highly toxic because of hydrogen cyanide content. o. of cinnamon volatile o. obtained by steam distillation from the leaves and twigs of Cinnamomum cassia (family Lauracea). A flavor in foods and perfumes. o. of citronella volatile o. obtained by steam distillation of fresh lemon grass. Contains citranellol; used as an insect repellent either on the skin or in the form of incense; also used as a perfume. o. of clove volatile o. obtained by steam distillation of the dried flower buds of Eugenia caryophyllata (family Myrtacea). Contains about 85% eugenol along with other constituents. Used in dentistry as a local anesthetic and component of temporary fillings of the teeth. Also used to flavor foods; strong, pungent odor. SYN: clove o.. concrete oils essential oils obtained by extraction with organic solvents; contain waxes and paraffins. o. of coriander volatile o. from the dried ripe fruit of Coriandrum sativum (family Umbelliferae). Flavoring in foods and alcoholic beverages. o. of crispmint SYN: o. of spearmint. o. of cubeb volatile o. of the unripe fruit of Piper cubeba (family Piperaceae). Formerly used as a urinary antiseptic. o. of curled mint SYN: o. of spearmint. o. of dwarf pine needles volatile o. from the fresh leaves of Pinus montana (family Pinaceae). Pleasant pine odor; used as a pharmaceutical aid (flavor and perfume). Has been used as an expectorant. essential oils plant products, usually somewhat volatile, giving the odors and tastes characteristic of the particular plant, thus possessing the essence, e.g., citral, pinene, camphor, menthane, terpenes; usually, the steam distillates of plants or oils of plants obtained by pressing out the rinds of a particular plant. SEE ALSO: volatile o.. ethereal o. SYN: volatile o.. o. of eucalyptus volatile o. from the fresh leaves of Eucalyptus globulus (family Myrtaceae) and some other species of Eucalyptus; native to Australia; pungent o. with a spicy, cooling taste. Has been used as an aromatic in inhalants, as an expectorant, anthelmintic, and local antiseptic. fatty o. an o. derived from both animals and plants; chemically, a glyceride of a fatty acid that, by substitution of the glycerine by an alkaline base, is converted into a soap; a fatty o., in contrast to a volatile o., is permanent, leaving a stain on an absorbent surface, and thus is not capable of distillation; it is obtained by expression or extraction; the consistency varies with the temperature, some being liquid (o.'s proper), others semisolid (fats), and others solid (tallows) at ordinary temperatures; both liquid and semisolid oils are congealed by cold and the solids are liquified by heat. SYN: fixed o.. o. of fennel volatile o. from the dried fruit of Foeniculum vulgare (family Umbelliferae). An aromatic o. with the odor and taste of fennel, similar to anise; used as a flavoring agent in pharmaceuticals. Has been used as a carminative. fixed o. SYN: fatty o.. fusel o. a mixture of side products of alcoholic fermentation; consists primarily of alcohols ( e.g., amyl, propyl, isoamyl, and isobutyl alcohols). joint o. SYN: synovial fluid. jojoba o. a liquid wax ester mixture extracted from ground or crushed seeds from Simmondsia chinensis and S. californica (family Buxaceae), desert shrubs native to Arizona, California, and northern Mexico. Used extensively in cosmetics for alleged skin softening and lubricating properties; other uses include as lubricant, fuel, chemical feedstock, substitute for sperm whale o.. SYN: o. of jojoba. o. of jojoba SYN: jojoba o.. o. of juniper volatile o. from the dried ripe fruit (berries) of Juniperus communis (family Cupressaceae). Formerly used as a diuretic. Used in perfumery. SYN: juniper berry o.. o. of lavender volatile o. from fresh flowering tops of Lavandula officinalis (family Labiatae). Aromatic o. used in perfume and as a flavoring agent. Has been used as a carminative. o. of lemon volatile o. expressed from fresh peel of Citrus limonum (family Rutaceae). Aromatic o. used for flavoring pharmaceuticals, liqueurs, pastry, foods, and beverages and in perfumes. o. of lemon grass volatile o. from Cymbopogon citratus and of C. flexuosus (family Gramineae). Used in perfumery and as a source of citral for the synthesis of vitamin A. Lorenzo o. a mixture of four parts glyceryl trioleate and one part glyceryl trierucate; used in treatment of adrenoleukodystrophy. [for Lorenzo Odone, a child with adrenoleukodystrophy, whose family's discovery and support of this agent were dramatized in the U.S. film Lorenzo's O. (1992)] olive o. The expressed o. of the fruit of Olea europaea; used as a cholagogue, laxative, and emollient, in the preparation of liniments, and in the preparation of foods. palm o. an o. obtained from the seeds of Elaeis guineensis (family Palmae); used in the manufacture of soap, liniments, and ointments and also in foods. o. of pennyroyal either American or European. The former is a volatile o. derived from the flowering tops and leaves of Hedeoma pulegioides (family Labiatae). Contains pulegone and ketones. European is o. of pulegium; a volatile o. from Mentha pulegium (family Labiatae); about 85% pulegone. Has been used as an aromatic carminative, abortifacient, and insect repellent. o. of peppermint a volatile o. containing menthol (not less than 50% of total) obtained by steam distillation from the fresh flowering plant Mentha piperita (family Labiatae). Used as a pharmaceutical aid (flavor) and in flavoring liqueurs; a carminative. red o. [C.I. 26125] a weakly acid diazo o.-soluble dye, used in histologic demonstration of neutral fats. rock o. (rok oyl) SYN: petroleum. o. of rose a volatile o. from the fresh flowers of Rosa gallica and R. damascena and other members of the Rosaceae family. Used largely in perfumery, ointments, and toilet preparations. SYN: attar of rose, essence of rose, otto of rose. o. of spearmint volatile o. from the flowering tops of Mentha spicata (family Labiatae, pharmaceutical aid (flavor) and a carminative. SYN: o. of crispmint, o. of curled mint. sweet birch o. SYN: methyl salicylate. o. of turpentine volatile o. distilled from the oleoresin and obtained from Pinus palastrus (family Pinaceae) and other species of Pinus yielding terpene oils. Solvent for oils, resins, varnishes; also used as vehicle, thinner, and remover of o.-based paints; rubefacient; has been used as a counterirritant in liniments. volatile o. a substance of oily consistency and feel, derived from a plant and containing the principles to which the odor and taste of the plant are due (essential o.); in contrast to a fatty o., a volatile o. evaporates when exposed to the air and thus is capable of distillation; it may also be obtained by expression or extraction; many volatile oils, identical to or closely resembling the natural oils, can be made synthetically. Volatile oils are used in medicine as stimulants, stomachics, correctives, and carminatives, and for purposes of flavoring ( e.g., peppermint o.). SYN: ethereal o.. o. of wormwood volatile o. from leaves and tops of Artemisia absinthium (family Compositae). Thujol alcohol and acetate; thujone (a powerful convulsant), phellandrene, cadinene; also a blue o.. Used in flavoring of vermouth and, formerly, in absinthe.

oil of vitriol
SYN: sulfuric acid.

ointment (oynt′ment)
A semisolid preparation usually containing medicinal substances and intended for external application. O. bases used as vehicles fall into four general classes: 1) Hydrocarbon bases (oleaginous o. bases) keep medicaments in prolonged contact with the skin, act as occlusive dressings, and are used chiefly for emollient effects. 2) Absorption bases either permit the incorporation of aqueous solutions with the formation of a water-in-oil emulsion or are water-in-oil emulsions that permit the incorporation of additional quantities of aqueous solutions; such bases permit better absorption of some medicaments and are useful as emollients. 3) Water-removable bases (creams) are oil-in-water emulsions containing petrolatum, anhydrous lanolin, or waxes; they may be washed from the skin with water and are thus more acceptable for cosmetic reasons; they favor absorption of serous discharges in dermatologic conditions. 4) Water-soluble bases (greaseless o. bases) contain only water-soluble substances. SEE ALSO: cerate. SYN: salve, uncture, unguent. [O. Fr. oignement; L. unguo, pp. unctus, to smear] blue o. a grease-based o. containing 20% finely divided metallic mercury, formerly widely used for local application to the skin for the destruction of body lice. Risk is associated with transdermal absorption of mercury and a local dermatitis. SYN: mild mercurial o.. eye o. SYN: ophthalmic o.. hydrophilic o. an o. base consisting of 25% each of white petrolatum and stearyl alcohol, 12% propyl glycol emulsified in 37% water by 1% of lauryl sulfate; preserved with paraben. Suitable for the incorporation of numerous drugs intended for local application; a washable o. base. mild mercurial o. SYN: blue o.. ophthalmic o. a special o. for application to the eye that must be free from particles and must be nonirritating to the eye. SYN: eye o., oculentum.

Reiji (1930–1975) and Tuneko, 20th century Japanese molecular biologists. See O. fragment.

Suffix denoting that a substance is an alcohol or a phenol.

olamine (ol′a-men)
USAN-approved contraction for ethanolamine.

Michael C., 20th century English physician. See O. syndrome.

oleaginous (o-le-aj′i-nus)
Oily or greasy. [L. oleagineus, pertaining to olea, the olive tree]

oleander (o-le-an′der)
The bark and leaves of Nerium o. (family Apocynaceae), a shrub of the eastern Mediterranean; formerly used as a diuretic and heart tonic.

oleandomycin phosphate (o-le-an-do-mi′sin)
An antibiotic substance produced by species of Streptomyces antibioticus; effective against staphylococci, streptococci, pneumococci, and some Gram-negative bacteria.

oleate (o′le-at)
1. A salt of oleic acid. 2. A pharmacopeial preparation consisting of a combination or solution of an alkaloid or metallic base in oleic acid, used as an inunction.

olecranon (o-lek′ra-non, o′le-kra′non) [TA]
The prominent curved proximal extremity of the ulna, the upper and posterior surface of which gives attachment to the tendon of the triceps muscle, the anterior surface entering into the formation of the trochlear notch. SYN: elbow bone, o. process, point of elbow, tip of elbow. [G. the head or point of the elbow, fr. olene, ulna, + kranion, skull, head]

olefin (o′le-fin)
SYN: alkene.

oleic acid (o-le′ik)
An unsaturated fatty acid that is the most widely distributed and abundant fatty acid in nature; used commercially in the preparation of oleates and lotions, and as a pharmaceutical solvent. Cf.:elaidic acid. [L. oleum, oil]

olein (o′le-in)
Trioleoyl glycerol; glyceryl trioleate;a triacylglycerol, solely containing oleoyl moieties, found in fats and oils. SYN: triolein.

Oil. SEE ALSO: eleo-. [L. oleum]

oleogomenol (o′le-o-go′men-ol)
SYN: gomenol.

oleogranuloma (o′le-o-gran-u-lo′ma)
SYN: lipogranuloma.

oleoma (o-le-o′ma)
SYN: lipogranuloma.


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