x

• xbeing one more than nine
• X chromosomethe sex chromosome that is present in both sexes: singly in males and doubly in females
• X raya radiogram made by exposing photographic film to X rays; used in medical diagnosis
• x raysThe Röntgen rays; -- so called by their discoverer because of their enigmatical character.
• x-axisthe horizontal axis in a plane coordinate system
• X-linkedrelating to genes or characteristics or conditions carried on the X chromosome
• X-linked dominant inheritancehereditary pattern in which a dominant gene on the X chromosome causes a characteristic to be manifested in the offspring
• X-linked genea gene located on an X chromosome
• X-linked recessive inheritancehereditary pattern in which a recessive gene on the X chromosome results in the manifestation of characteristics in male offspring and a carrier state in female offspring
• X-linked SCIDSCID in male children resulting from mutation of a gene that codes for a protein on the surface of T cells that allows them to develop a growth factor receptor
• X-OR circuitgate for exclusive OR; a circuit in a computer that fires only if only one of its inputs fire
• X-radiationobtaining images by the use of X rays
• x-raya radiogram made by exposing photographic film to X rays; used in medical diagnosis
• X-ray diffractionthe scattering of X rays by the atoms of a crystal; the diffraction pattern shows structure of the crystal
• X-ray filmphotographic film used to make X-ray pictures
• X-ray machinean apparatus that provides a source of X rays
• X-ray photographa radiogram made by exposing photographic film to X rays; used in medical diagnosis
• X-ray photographyradiography that uses X-rays to produce a roentgenogram
• X-ray picturea radiogram made by exposing photographic film to X rays; used in medical diagnosis
• X-ray therapythe therapeutic use of X rays
• x-ray tubeA vacuum tube suitable for producing Röntgen rays.
• X-rayingobtaining images by the use of X rays
• x-raysThe Röntgen rays; -- so called by their discoverer because of their enigmatical character.
• X-SCIDSCID in male children resulting from mutation of a gene that codes for a protein on the surface of T cells that allows them to develop a growth factor receptor
• Xanaxan antianxiety agent (trade name Xanax) of the benzodiazepine class
• xanthamideAn amido derivative of xanthic acid obtained as a white crystalline substance, C2H5O.CS.NH2; -- called also xanthogen amide.
• xanthatea salt or ester of xanthic acid
• xanthelasmaxanthoma of the eyelids; occurs chiefly in the elderly
• xanthemiaexcess carotene in the blood stream; can cause the skin to turn a pale yellow or red color
• xanthianOf or pertaining to Xanthus, an ancient town on Asia Minor; -- applied especially to certain marbles found near that place, and now in the British Museum.
• xanthicTending toward a yellow color, or to one of those colors, green being excepted, in which yellow is a constituent, as scarlet, orange, etc.
• xanthic acidany of a class of unstable organic acids containing sulphur
• xanthideA compound or derivative of xanthogen. [Archaic]
• xanthidiumA genus of minute unicellular algæ of the desmids. These algæ have a rounded shape and are armed with glochidiate or branched aculei. Several species occur in ditches, and others are found fossil in flint or hornstone.
• xanthin(Physiol. Chem.) A crystalline nitrogenous body closely related to both uric acid and hypoxanthin, present in muscle tissue, and occasionally found in the urine and in some urinary calculi. It is also present in guano. So called from the yellow color of certain of its salts (nitrates).
• xanthinecrystalline oxidation product of the metabolism of nucleoproteins; precursor of uric acid; found in many organs and in urine
• xanthinineA complex nitrogenous substance related to urea and uric acid, produced as a white powder; -- so called because it forms yellow salts, and because its solution forms a blue fluorescence like quinine.
• xanthiumA genus of composite plants in which the scales of the involucre are united so as to form a kind of bur; cocklebur; clotbur.
• xantho-A combining form from Gr. xanqo`s yellow; as in xanthocobaltic salts. Used also adjectively in chemistry.
• xanthocarpousHaving yellow fruit.
• xanthochroiA division of the Caucasian races, comprising the lighter- colored members. The Xanthochroi, or fair whites, . . . are the prevalent inhabitants of Northern Europe, and the type may be traced into North Africa, and eastward as far as Hindostan. Tylor.
• xanthochroicHaving a yellowish or fair complexion; of or pertaining to the Xanthochroi.
• xanthochroidHaving a yellowish or fair complexion. -- n. A person having xanthochroid traits.
• xanthochroismAbnormal coloration of feathers in which yellow replaces the normal color, as in certain parrots. It is commonly due to lack of the dark pigment which with yellow forms green.
• xanthodontousHaving yellow teeth.
• xanthogen(a) The hypothetical radical supposed to be characteristic of xanthic acid. [Archaic] (b) Persulphocyanogen. [R.]
• xanthogenateA salt of xanthic acid.
• xanthogenicProducing a yellow color or compound; xanthic. See Xanthic acid, under Xanthic.
• xanthomaa skin problem marked by the development (on the eyelids and neck and back) of irregular yellow nodules; sometimes attributable to disturbances of cholesterol metabolism
• xanthoma disseminatumrare chronic xanthoma of adults in which orange or brownish papules develop on many surfaces of the body
• xanthoma multiplexwidespread xanthomas (especially on elbows and knees); often associated with a disorder of lipid metabolism
• xanthomatosiswidespread xanthomas (especially on elbows and knees); often associated with a disorder of lipid metabolism
• xanthomatousOf or pertaining to xanthoma.
• xanthomelanousOf or pertaining to the lighter division of the Melanochroi, or those races having an olive or yellow complexion and black hair.
• xanthomonadbacteria producing yellow non-water-soluble pigments; some pathogenic for plants
• Xanthomonasa genus of bacteria similar to Pseudomonas but producing a yellow pigment that is not soluble in water
• xanthophaneThe yellow pigment present in the inner segments of the retina in animals. See Chromophane.
• Xanthophyceaeyellow-green algae
• xanthophylyellow carotenoid pigments in plants and animal fats and egg yolks
• xanthophyllyellow carotenoid pigments in plants and animal fats and egg yolks
• xanthopousHaving a yellow stipe, or stem.
• xanthoproteicPertaining to, or derived from, xanthoprotein; showing the characters of xanthoprotein; as, xanthoproteic acid; the xanthoproteic reaction for albumin.
• xanthoproteinA yellow acid substance formed by the action of hot nitric acid on albuminous or proteid matter. It is changed to a deep orange- yellow color by the addition of ammonia.
• xanthopsiavisual defect in which objects appear to have a yellowish hue; sometimes occurs in cases of jaundice
• xanthopuccineOne of three alkaloids found in the root of the yellow puccoon (Hydrastis Canadensis). It is a yellow crystalline substance, and resembles berberine.
• xanthorhamninA glucoside extracted from Persian berries as a yellow crystalline powder, used as a dyestuff.
• xanthorhizaA genus of shrubby ranunculaceous plants of North America, including only the species Xanthorhiza apiifolia, which has roots of a deep yellow color; yellowroot. The bark is intensely bitter, and is sometimes used as a tonic.
• xanthorhoeaA genus of endogenous plants, native to Australia, having a thick, sometimes arborescent, stem, and long grasslike leaves. See Grass tree.
• Xanthorrhoeaceaeone of many subfamilies into which some classification systems subdivide the Liliaceae but not widely accepted
• Xanthorroeagrass trees; sometimes placed in family Xanthorrhoeaceae
• xanthoseAn orange-yellow substance found in pigment spots of certain crabs.
• xanthosisan abnormal yellow discoloration of the skin
• Xanthosomatropical American tuberous perennials
• Xanthosoma atrovirenstropical American aroid having edible tubers that are cooked and eaten like yams or potatoes
• Xanthosoma sagittifoliumtropical American aroid having edible tubers that are cooked and eaten like yams or potatoes
• xanthospermousHaving yellow seeds.
• xanthousof the color intermediate between green and orange in the color spectrum; of something resembling the color of an egg yolk
• xanthoxyleneA liquid hydrocarbon of the terpene series extracted from the seeds of a Japanese prickly ash (Xanthoxylum pipertium) as an aromatic oil.
• xanthoxylumA genus of prickly shrubs or small trees, the bark and rots of which are of a deep yellow color; prickly ash. Note: The commonest species in the Northern United States is Xanthoxylum Americanum. See Prickly ash, under Prickly.
• Xantusiidaenight lizards
• XavierSpanish missionary and Jesuit who establish missionaries in Japan and Ceylon and the East Indies (1506-1552)
• xcbeing ten more than eighty
• xcibeing one more than ninety
• xciibeing two more than ninety
• xciiibeing three more than ninety
• xcivbeing four more than ninety
• xclbeing ten more than one hundred eighty
• xcvbeing five more than ninety
• xcvibeing six more than ninety
• xcviibeing seven more than ninety
• xcviiibeing eight more than ninety
• Xea colorless odorless inert gaseous element occurring in the earth's atmosphere in trace amounts
• xebecA small three-masted vessel, with projecting bow stern and convex decks, used in the Mediterranean for transporting merchandise, etc. It carries large square sails, or both. Xebecs were formerly armed and used by corsairs.
• xemeAn Arctic fork-tailed gull (Xema Sabinii).
• Xenarthraarmadillos; American anteaters; sloths
• xenelasiaA Spartan institution which prohibited strangers from residing in Sparta without permission, its object probably being to preserve the national simplicity of manners.
• Xenicidaealternative names for the family comprising the New Zealand wrens
• Xenicustype genus for the Xenicidae
• Xenicus gilviventrisshort-tailed bird resembling a wren
• xeniumA present given to a guest or stranger, or to a foreign ambassador.
• xenodochiumA house for the reception of strangers. (b) In the Middle Ages, a room in a monastery for the reception and entertainment of strangers and pilgrims, and for the relief of paupers. [Called also Xenodocheion.]
• xenodochyReception of strangers; hospitality. [R.]
• xenogamyCross fertilization.
• xenogeneicdenoting or relating to cells or tissues from individuals belonging to different species
• xenogenesisthe alternation of two or more different forms in the life cycle of a plant or animal
• xenogeneticOf or pertaining to xenogenesis; as, the xenogenetic origin of microzymes. Huxley.
• xenografttissue from an animal of one species used as a temporary graft (as in cases of severe burns) on an individual of another species
• xenolith(geology) a piece of rock of different origin from the igneous rock in which it is embedded
• xenomaniaA mania for, or an inordinate attachment to, foreign customs, institutions, manners, fashions, etc. [R.] Saintsbury.
• xenomiA suborder of soft-rayed fresh-water fishes of which the blackfish of Alaska (Dallia pectoralis) is the type.
• xenona colorless odorless inert gaseous element occurring in the earth's atmosphere in trace amounts
• XenophanesGreek philosopher (560-478 BC)
• xenophobiaa fear of foreigners or strangers
• xenophobicsuffering from xenophobia; having abnormal fear or hatred of the strange or foreign
• XenophonGreek general and historian; student of Socrates (430-355 BC)
• Xenopodidaein some classifications the family of the genus Xenopus which is otherwise included in the family Pipidae
• xenopterygiiA suborder of fishes including Gobiesox and allied genera. These fishes have soft-rayed fins, and a ventral sucker supported in front by the pectoral fins. They are destitute of scales.
• Xenopusan African clawed frog; in some classifications made the type genus of a separate family Xenopodidae
• Xenopus laevisa tongueless frog native to Africa; established in the United States as result of release of laboratory and aquarium animals
• XenorhyncusEast Indian and Australian storks
• Xenorhyncus asiaticuslarge mostly white Australian stork
• Xenosauridaemonotypic family of Mexican lizards
• Xenosaurustype and sole genus of Xenosauridae: slender-bodied Mexican lizards having the upper surface covered with tiny granules and tubercles
• xenotimea brown-to-yellow mineral that is a phosphate of yttrium in crystalline form
• xenotransplanta surgical procedure in which tissue or whole organs are transfered from one species to another species
• xenotransplantationa surgical procedure in which tissue or whole organs are transfered from one species to another species
• xenurineA cabassou.
• xenylThe radical characteristic of xenylic compounds.
• xenylicPertaining to, derived from, designating, certain amido compounds obtained by reducing certain nitro derivatives of diphenyl.
• xeranthemumany plant of the genus Xeranthemum native to southern Europe having chaffy or silvery flower heads with purplish tubular flowers
• Xeranthemum annuummostly widely cultivated species of everlasting flowers having usually purple flowers; southern Europe to Iran; naturalized elsewhere
• xeraphimAn old money of account in Bombay, equal to three fifths of a rupee.
• xeresSherry. See Sherry.
• xericbeing deficient in moisture
• xerifA shereef.
• xeriffA gold coin formerly current in Egypt and Turkey, of the value of about 9s. 6d., or about $2.30; -- also, in Morocco, a ducat.
• Xerobatespossible new genus for desert and Texas tortoises based on recent research
• xerodermaa mild form of ichthyosis characterized by abnormal dryness and roughness of the skin
• xeroderma pigmentosuma rare genetic condition characterized by an eruption of exposed skin occurring in childhood and photosensitivity with severe sunburn; inherited as a recessive autosomal trait in which DNA repair processes are defective so they are more likely to chromosome breaks and cancers when exposed to ultraviolet light
• xerodermiaa mild form of ichthyosis characterized by abnormal dryness and roughness of the skin
• xerographicof or relating to xerography
• xerographic copiera duplicator (trade mark Xerox) that copies graphic matter by the action of light on an electrically charged photoconductive insulating surface in which the latent image is developed with a resinous powder
• xerographic printera page printer that uses the xerographic process
• xerographyforming an image by the action of light on a specially coated charged plate; the latent image is developed with powders that adhere only to electrically charged areas
• xeromaabnormal dryness of the conjunctiva and cornea of the eyes; may be due to a systemic deficiency of vitamin A
• xeronateA salt of xeronic acid.
• xeronicPertaining to, or designating, an acid, C8H12O4, related to fumaric acid, and obtained from citraconic acid as an oily substance having a bittersweet taste; -- so called from its tendency to form its anhydride.
• xerophagyAmong the primitive Christians, the living on a diet of dry food in Lent and on other fasts.
• xerophileplant adapted for life with a limited supply of water; compare hydrophyte and mesophyte
• xerophilousDrought-loving; able withstand the absence or lack of moisture. Plants which are peculiarly adapted to dry climates are termed by De Candolle xerophilous. Goodale.
• xerophilous plantplant adapted for life with a limited supply of water; compare hydrophyte and mesophyte
• xerophthalmiaabnormal dryness of the conjunctiva and cornea of the eyes; may be due to a systemic deficiency of vitamin A
• xerophthalmusabnormal dryness of the conjunctiva and cornea of the eyes; may be due to a systemic deficiency of vitamin A
• xerophthalmyXerophthalmia.
• Xerophyllumsmall genus of North American herbs having grasslike basal leaves: squaw grass; sometimes placed in family Melanthiaceae
• Xerophyllum tenaxplant of western North America having woody rhizomes and tufts of stiff grasslike basal leaves and spikes of creamy white flowers
• xerophyteplant adapted for life with a limited supply of water; compare hydrophyte and mesophyte
• xerophyticadapted to a xeric (or dry) environment
• xerophytic plantplant adapted for life with a limited supply of water; compare hydrophyte and mesophyte
• xeroradiographyradiography using X-rays and xerographic (rather than roentgenographic) techniques
• xerostomiaabnormal dryness of the mouth resulting from decreased secretion of saliva
• xerotesthe condition of not containing or being covered by a liquid (especially water)
• xeroxa copy made by a xerographic printer
• xerox copya copy made by a xerographic printer
• Xerox machinea duplicator (trade mark Xerox) that copies graphic matter by the action of light on an electrically charged photoconductive insulating surface in which the latent image is developed with a resinous powder
• Xerxes Iking of Persia who led a vast army against Greece and won the battle of Thermopylae but was eventually defeated (519-465 BC)
• Xerxes the Greatking of Persia who led a vast army against Greece and won the battle of Thermopylae but was eventually defeated (519-465 BC)
• Xestobium rufovillosumbores through wood making a ticking sound popularly thought to presage death
• Xhosaa Bantu language closely related to Zulu
• xibeing one more than ten
• Xiana city of central China; capital of ancient Chinese empire 221-206 BC
• xiidenoting a quantity consisting of 12 items or units
• xiiibeing one more than twelve
• Ximenesia encelioidescoarse greyish-green annual yellow-flowered herb; southwestern United States to Mexico
• Xinjiangan autonomous province in far northwestern China on the border with Mongolia and Kazakhstan; the largest province in the People's Republic of China and the homeland of the Uighur people
• Xinjiang Uighur Autonomous Regionan autonomous province in far northwestern China on the border with Mongolia and Kazakhstan; the largest province in the People's Republic of China and the homeland of the Uighur people
• xiphias(Zoöl.) A genus of fishes comprising the common swordfish.
• Xiphias gladiuslarge toothless marine food fish with a long swordlike upper jaw; not completely cold-blooded i.e. they are able to warm their brains and eyes: worldwide in warm waters but feed on cold ocean floor coming to surface at night
• xiphidiumA genus of plants of the order Hæmodraceæ, having two-ranked, sword-shaped leaves.
• Xiphiidaecomprising the common swordfishes
• xiphioidOf, pertaining to, or resembling, a cetacean of the genus Xiphius or family Xiphiidæ.
• xiphiplastronThe posterior, or fourth, lateral plate in the plastron of turtles; -- called also xiphisternum.
• xiphisternum(a) The posterior segment, or extremity, of the sternum; -- sometimes called metasternum, ensiform cartilage, ensiform process, or xiphoid process. (b) The xiphiplastron. -- Xiph"i*ster"nal a.
• xiphium irisbulbous iris of western Mediterranean region having usually violet-purple flowers
• xiphiusA genus of cetaceans having a long, pointed, bony beak, usually two tusklike teeth in the lower jaw, but no teeth in the upper jaw.
• xiphodonAn extinct genus of artiodactylous mammals found in the European Tertiary formations. It had slender legs, didactylous feet, and small canine teeth.
• xiphoid(a) Like a sword; ensiform. (b) Of or pertaining to the xiphoid process; xiphoidian.
• xiphoid processsmallest of the three parts of the breastbone; articulates with the corpus sternum and the seventh rib
• xiphoidianXiphoid.
• xiphophyllousHaving sword-shaped leaves.
• xiphosuraSee Xiphura.
• Xiphosurus polyphemuslarge marine arthropod of the Atlantic coast of North America having a domed carapace that is shaped like a horseshoe and a stiff pointed tail; a living fossil related to the wood louse
• xiphuraSame as Limuloidea. Called also Xiphosura. X ray. See under Ray.
• Xishuangbanna Daia branch of the Tai languages
• xivbeing one more than thirteen
• xixbeing one more than eighteen
• Xizangan autonomous region of the Peoples Republic of China; located in the Himalayas
• xlbeing ten more than thirty
• xlibeing one more than forty
• xliibeing two more than forty