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, §§ 217, 270, 271. [ 1913 Webster ]

The form and value of X are from the Latin X, which is from the Greek Χ, 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. [ 1913 Webster ]

n. [ Xanthic + amide. ] (Chem.) An amido derivative of xanthic acid obtained as a white crystalline substance, C2H5O.CS.NH2; -- called also xanthogen amide. [ 1913 Webster ]

n. [ See Xanthic. ] (Chem.) A salt of xanthic; a xanthogenate. [ 1913 Webster ]

‖n. [ NL.; Gr. xanqo`s yellow + 'e`lasma a metal plate. ] (Med.) See Xanthoma. [ 1913 Webster ]

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. [ 1913 Webster ]

a. [ Gr. xanqo`s yellow: cf. F. xanthique. ] [ 1913 Webster ]

1. Tending toward a yellow color, or to one of those colors, green being excepted, in which yellow is a constituent, as scarlet, orange, etc. [ 1913 Webster ]

2. (Chem.) (a) Possessing, imparting, or producing a yellow color; as, xanthic acid. (b) Of or pertaining to xanthic acid, or its compounds; xanthogenic. (c) Of or pertaining to xanthin. [ 1913 Webster ]

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. [ 1913 Webster ]

n. [ See Xantho-. ] (Chem.) A compound or derivative of xanthogen. [ Archaic ] [ 1913 Webster ]

‖n.; pl. Xanthidia [ NL., fr. Gr. xanqo`s yellow. ] (Bot.) 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. [ 1913 Webster ]

n. [ Gr. xanqo`s yellow. ] 1. same as xanthine. [ 1913 Webster ]

2. (Chem.) A yellow insoluble coloring matter extracted from yellow flowers; specifically, the coloring matter of madder. [ Formerly written also xanthein. ] [ 1913 Webster ]

3. (Chem.) One of the gaseous or volatile decomposition products of the xanthates, and probably identical with carbon disulphide. [ Obs. ] [ 1913 Webster ]

{ n. Also }. [ Gr. xanqo`s yellow. ] (Physiol. Chem.) A type of purine obtainable as a white microcrystalline powder, C5H4O2N4, present in muscle tissue, in the liver, spleen, pancreas, and other organs, and also in urine (in small quantities) and some urinary calculi, and in the juices of certain plants; -- so called because it leaves a yellow residue when evaporated to dryness with nitric acid. It is also present in guano. Xanthine is closely related to uric acid. [ Webster 1913 Suppl. ]