Webster's Unabridged Dictionary - Letter X - Page 1

X () X, the twenty-fourth letter of the English alphabet, has three sounds; a compound nonvocal sound (that of ks), as in wax; a compound vocal sound (that of gz), as in example; and, at the beginning of a word, a simple vocal sound (that of z), as in xanthic. See Guide to Pronunciation, [sect] [sect] 217, 270, 271.

Note: The form and value of X are from the Latin X, which is from the Greek [Chi], which in some Greek alphabets had the value of ks, though in the one now in common use it represents an aspirated sound of k.

X (a.) Being one more than nine [syn: ten, 10, x].

X (n.) The cardinal number that is the sum of nine and one; the base of the decimal system [syn: ten, 10, X, tenner, decade].

X (n.) The 24th letter of the Roman alphabet [syn: X, x, ex].

X (n.) Street names for methylenedioxymethamphetamine [syn: Adam, ecstasy, XTC, go, disco biscuit, cristal, X, hug drug].

X (n.) Used in various speech and writing contexts (also in lowercase) in roughly its algebraic sense of "unknown within a set defined by context" (compare N).  Thus, the abbreviation 680x0 stands for 68000, 68010, 68020, 68030 or 68040, and 80x86 stands for Intel 80186, Intel 80286, Intel 80386 or Intel 80486.  A Unix hacker might write these as 680[0-4]0 and 80[1-4]86 or 680?0 and 80?86 respectively; see glob.

X (n.) [After the name of an earlier window system called ?W?] An over-sized, over-featured, over-engineered and incredibly over-complicated window system developed at MIT and widely used on Unix systems.

X () Used in various speech and writing contexts (also in lowercase) in roughly its algebraic sense of "unknown within a set defined by context" (compare N).  Thus, the abbreviation 680x0 stands for 68000, 68010, 68020, 68030 or 68040, and 80x86 stands for Intel 80186, Intel 80286, Intel 80386 or Intel 80486.  A Unix hacker might write these as 680[0-4]0 and 80[1-4]86 or 680?0 and 80?86 respectively; see glob.

X () An alternative name for the X Window System.

X () A suffix for the speed of a CD-ROM drive relative to standard music CDs (1x).  32x is common in September 1999. [{Jargon File] (1999-09-15)

X () In our alphabet being a needless letter has an added invincibility to the attacks of the spelling reformers, and like them, will doubtless last as long as the language.  X is the sacred symbol of ten dollars, and in such words as Xmas, Xn, etc., stands for Christ, not, as is popular supposed, because it represents a cross, but because the corresponding letter in the Greek alphabet is the initial of his name -- Xristos_.  If it represented a cross it would stand for St. Andrew, who "testified" upon one of that shape.  In the algebra of psychology x stands for Woman's mind.  Words beginning with X are Grecian and will not be defined in this standard English dictionary.

Xanadu (n.) 世外桃源;富於田園美的地方 A place of great beauty, luxury, and contentment.

Xanthamide (n.) (Chem.) An amido derivative of xanthic acid obtained as a white crystalline substance, C2H5O.CS.NH2; -- called also xanthogen amide.

Xanthate (n.) (Chem.) A salt of xanthic; a xanthogenate.

Xanthate (n.) A salt or ester of xanthic acid.

Xanthoma (n.) (Med.) A skin disease marked by the development or irregular yellowish patches upon the skin, especially upon the eyelids; -- called also xanthelasma.

Xanthelasma (n.) (Med.) See Xanthoma.

Xanthelasma (n.) Xanthoma of the eyelids; occurs chiefly in the elderly.

Xanthian (a.) Of 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.

Xanthic (a.) Tending toward a yellow color, or to one of those colors, green being excepted, in which yellow is a constituent, as scarlet, orange, etc.

Xanthic (a.) (Chem.) Possessing, imparting, or producing a yellow color; as, xanthic acid.

Xanthic (a.) (Chem.) Of or pertaining to xanthic acid, or its compounds; xanthogenic.

Xanthic (a.) (Chem.) Of or pertaining to xanthin.

Xanthic acid (Chem.), A heavy, astringent, colorless oil, C2H5O.CS.SH, having a pungent odor. It is produced by leading carbon disulphide into a hot alcoholic solution of potassium hydroxide. So called from the yellow color of many of its salts. Called also xanthogenic acid.

Xanthic colors (Bot.), Those colors (of flowers) having some tinge of yellow; -- opposed to cyanic colors. See under Cyanic.

Xanthide (n.) A compound or derivative of xanthogen.

Xanthidia (n. pl. ) of Xanthidium.

Xanthidium (n.) A genus of minute unicellular algae of the desmids. These algae 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 (n.) 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).

Xanthin (n.) A yellow insoluble coloring matter extracted from yellow flowers; specifically, the coloring matter of madder.

Xanthin (n.) One of the gaseous or volatile decomposition products of the xanthates, and probably identical with carbon disulphide.

Xanthinine (n.) A 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.

Xanthium (n.) A 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.

Xanthocarpous (a.) Having yellow fruit.

Xanthochroi (n. pl.) A division of the Caucasian races, comprising the lighter-colored members.

Xanthochroic (a.) Having a yellowish or fair complexion; of or pertaining to the Xanthochroi.

Xanthodontous (a.) Having yellow teeth.

Xanthogen (n.) The hypothetical radical supposed to be characteristic of xanthic acid.

Xanthogen (n.) Persulphocyanogen.

Xanthogenate (n.) A salt of xanthic acid.

Xanthogenic (a.) Producing a yellow color or compound; xanthic. See Xanthic acid, under Xanthic.

Xanthoma (n.) A skin disease marked by the development or irregular yellowish patches upon the skin, especially upon the eyelids; -- called also xanthelasma.

Xanthophane (n.) The yellow pigment present in the inner segments of the retina in animals. See Chromophane.

Xanthophyll (n.) A yellow coloring matter found in yellow autumn leaves, and also produced artificially from chlorophyll; -- formerly called also phylloxanthin.

Xanthopous (a.) Having a yellow stipe, or stem.

Xanthoproteic (a.) Pertaining to, or derived from, xanthoprotein; showing the characters of xanthoprotein; as, xanthoproteic acid; the xanthoproteic reaction for albumin.

Xanthoprotein (n.) A 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.

Xanthopuccine (n.) One of three alkaloids found in the root of the yellow puccoon (Hydrastis Canadensis). It is a yellow crystalline substance, and resembles berberine.

Xanthorhamnin (n.) A glucoside extracted from Persian berries as a yellow crystalline powder, used as a dyestuff.

Xanthorhiza (n.) A 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.

Xanthorhoea (n.) A genus of endogenous plants, native to Australia, having a thick, sometimes arborescent, stem, and long grasslike leaves. See Grass tree.

Xanthose (n.) An orange-yellow substance found in pigment spots of certain crabs.

Xanthosis (n.) The yellow discoloration often observed in cancerous tumors.

Xanthospermous (a.) Having yellow seeds.

Xanthous (a.) Yellow; specifically (Ethnol.), of or pertaining to those races of man which have yellowish, red, auburn, or brown hair.

Xanthoxylene (n.) A liquid hydrocarbon of the terpene series extracted from the seeds of a Japanese prickly ash (Xanthoxylum pipertium) as an aromatic oil.

Xanthoxylum (n.) A genus of prickly shrubs or small trees, the bark and rots of which are of a deep yellow color; prickly ash.

Xebec (n.) A 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.

Xeme (n.) An Arctic fork-tailed gull (Xema Sabinii).

Xenelasia (n.) A Spartan institution which prohibited strangers from residing in Sparta without permission, its object probably being to preserve the national simplicity of manners.

Xenia (n. pl. ) of Xenium.

Xenium (n.) A present given to a guest or stranger, or to a foreign ambassador.

Xenodochium (n.) A house for the reception of strangers.

Xenodochium (n.) 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.]

Xenodochy (n.) Reception of strangers; hospitality.

Xenogamy (n.) Cross fertilization.

Xenogenesis (n.) Same as Heterogenesis.

Xenogenesis (n.) The fancied production of an organism of one kind by an organism of another.

Xenogenetic (a.) Of or pertaining to xenogenesis; as, the xenogenetic origin of microzymes.

Xenomania (n.) A mania for, or an inordinate attachment to, foreign customs, institutions, manners, fashions, etc.

Xenomi (n. pl.) A suborder of soft-rayed fresh-water fishes of which the blackfish of Alaska (Dallia pectoralis) is the type.

Xenophobe (n.)  [ C ]  排外者;恐外者 A  person  who  strongly  dislikes  or  fears  foreigners,  their  customs, their  religions, etc.

Xenopterygii (n. pl.) A 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.

Xenotime (n.) A native phosphate of yttrium occurring in yellowish-brown tetragonal crystals.

Xenurine (n.) A cabassou.

Xenyl (n.) The radical characteristic of xenylic compounds.

Xenylic (a.) Pertaining to, derived from, designating, certain amido compounds obtained by reducing certain nitro derivatives of diphenyl.

Xeraphim (n.) An old money of account in Bombay, equal to three fifths of a rupee.

Xeres (n.) Sherry. See Sherry.

Xerif (n.) A shereef.

Xeriff (n.) A gold coin formerly current in Egypt and Turkey, of the value of about 9s. 6d., or about $2.30; -- also, in Morocco, a ducat.

Xeroderma (n.) Ichthyosis.

Xeroderma (n.) A skin disease characterized by the presence of numerous small pigmented spots resembling freckles, with which are subsequently mingled spots of atrophied skin.

Xeronate (n.) A salt of xeronic acid.

Xeronic (a.) Pertaining 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.

Xerophagy (n.) Among the primitive Christians, the living on a diet of dry food in Lent and on other fasts.

Xerophilous (a.) Drought-loving; able withstand the absence or lack of moisture.

Xerophthalmia (n.) An abnormal dryness of the eyeball produced usually by long-continued inflammation and subsequent atrophy of the conjunctiva.

Xerophthalmy (n.) Xerophthalmia.

Xiphias (n.) A genus of fishes comprising the common swordfish.

Xiphias (n.) The constellation Dorado.

Xiphias (n.) A comet shaped like a sword

Xiphidium (n.) A genus of plants of the order Haemodraceae, having two-ranked, sword-shaped leaves.

Xiphioid (a.) Of, pertaining to, or resembling, a cetacean of the genus Xiphius or family Xiphiidae.

Xiphiplastra (n. pl. ) of Xiphiplastron

Xiphiplastron (n.) The posterior, or fourth, lateral plate in the plastron of turtles; -- called also xiphisternum.

Xiphisterna (n. pl. ) of Xiphisternum

Xiphisternum (n.) 劍胸骨 The posterior segment, or extremity, of the sternum; -- sometimes called {metasternum}, {ensiform cartilage}, {ensiform process}, or {xiphoid process}.

Xiphisternum (n.) The xiphiplastron. -- {Xiph"i*ster"nal} a.

Xiphius (n.) A genus of cetaceans having a long, pointed, bony beak, usually two tusklike teeth in the lower jaw, but no teeth in the upper jaw.

Xiphodon (n.) An 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.

Xiphoid (a.) Of or pertaining to the xiphoid process; xiphoidian.

Xiphoidian (a.) Xiphoid.

Xiphophyllous (a.) Having sword-shaped leaves.

Xiphosura (n. pl.) See Xiphura.

Xiphura (n. pl.) Same as Limuloidea. Called also Xiphosura.

Xl (a.) The Roman number symbolizing the value forty.

Syn: forty, 40, twoscore.

Xl (a.) Being ten more than thirty [syn: forty, 40, xl, twoscore].

Xl (n.) The cardinal number that is the product of ten and four [syn: forty, 40, XL].

Xylamide (n.) An acid amide derivative of xylic acid, obtained as a white crystalline substance.

Xylanthrax (n.) Wood coal, or charcoal; -- so called in distinction from mineral coal.

Xylate (n.) A salt of xylic acid.

Xylem (n.) That portion of a fibrovascular bundle which has developed, or will develop, into wood cells; -- distinguished from phloem.

Xylene (n.) (Chem.) Any of a group of three metameric hydrocarbons of the aromatic series, found in coal and wood tar, and so named because found in crude wood spirit. They are colorless, oily, inflammable liquids, C6H4.(CH3)2, being dimethyl benzenes, and are called respectively orthoxylene, metaxylene, and paraxylene. Called also xylol.

Note: Each of these xylenes is the nucleus and prototype of a distinct series of compounds.

Xylene (n.) A colorless flammable volatile liquid hydrocarbon used as a solvent [syn: xylene, xylol].

Xylenol (n.) (Chem.) Any one of six metameric phenol derivatives of xylene, obtained as crystalline substances, (CH3)2.C6H3.OH.

Xyletic (a.) (Chem.) Pertaining to, or designating, a complex acid related to mesitylenic acid, obtained as a white crystalline substance by the action of sodium and carbon dioxide on crude xylenol.

Xylic (a.) (Chem.) Pertaining to, derived from, or related to, xylene; specifically, designating any one of several metameric acids produced by the partial oxidation of mesitylene and pseudo-cumene.

Xylidic (a.) (Chem.) Pertaining to, or designating, either one of two distinct acids which are derived from xylic acid and related compounds, and are metameric with uvitic acid.

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