The twenty-fourth letter of the modern and the twenty-first of the ancient Roman alphabet, corresponding in form and position to the Greek Χ. The early Greek forms ?? represented the aspirated voiceless velar /kh/ in the Ionian alphabet, and /ks/ in the Chalcidian alphabet. (In the former, /ks/ was denoted by ?, in the latter, /kh/ was denoted by ?.) Χ was adopted by the Latins with the value /ks/ from the Greek alphabet introduced into Italy. The ancient Roman name of the letter was ix, which is that given by Ælfric in his Grammar (c1000). Words having initial x (pronounced as z) in English are nearly all of Greek origin; a few, as xebec, Xerez, have x representing early Spanish x (now j). In Old English x was used medially and finally as a variant spelling of cs (whether original or standing for sc), e.g. æx, eax = æcus, acus, æsc axe n.¹, áxian = ácsian, áscian to ask v., fixas, plural of fisc fish n.¹, fixian = fiscian to fish v.¹, waxan = wascan to wash v. Other variants are cx, hx, xs, cxs, hxs, as meohx, micxen mixen n., axsan ash n.² Similar spellings occur in the Cotton MS. of Cursor Mundi, e.g. flexs(s flesh, wexs wash, fixses fishes; the same MS. has the unexplained spellings fux(o)l, foux(u)l, etc. of fowl n. In East Anglian texts of the 14th to the 16th century x is frequently written for initial sc, sch in xal shall, xuld should; xsal also is found in the Paston Letters; instances of other words so written are only occasional, e.g. xad shed (past participle), xowyn shove, xuldrys shoulders. Initial x stands for sh (or s) in early forms of some oriental words, as xerif shereef n. (after early Spanish xerife), xaraffe, -aff saraf n., and Xinto Shinto n. and adj. Other temporary uses of x, but with its normal value /ks/, are found in the once general axes, axis access n., hunx hunks n., and the less common exelent excellent adj. and adv., exite excite v.; on the other hand pox = pocks has become permanent, and sox has been adopted, originally in the hosiery trade, as a convenient shortening of socks.The phonetic values of x in English are three, of which the commonest is /ks/, as in axis /ˈæksɪs/, buxom /ˈbʌksəm/, doxology /dɒkˈsɒlədʒɪ/, excuse /ɪkˈskjuːs/, expense /ɪkˈspɛns/, oxen /ˈɒks(ə)n/, proximity /prɒkˈsɪmɪtɪ/, tax /tæks/. The pronunciation of the prefix ex- followed by a vowel or h varies according as it bears the stress or not, the general rule being that ˈex— = /ɛks/ and ex—ˈ = /ɪɡz/, as exile /ˈɛksaɪl/, exact /ɪɡˈzækt/, exhort /ɪɡˈzɔːt/; but there is considerable variety in individual words and individual usage: see etymological note at ex- prefix¹. The same general principle governs the pronunciation of anxious /ˈæŋkʃəs/, anxiety /æŋɡˈzaɪɪtɪ/, luxury /ˈlʌksjʊərɪ//ˈlʌkʃərɪ/, luxurious /lʌɡˈzjʊərɪəs//lʌɡˈʒʊərɪəs/ Alexander /ælɪɡˈzɑːndə(r)//-æ-/, Alexandrine /ælɪɡˈzɑːndrɪn//-æ-/; but here also individual usage varies. The third value /z/, arising from a reduction of /ɡz/, is given in all cases to initial x, as Xerxes /ˈzɜːksiːz/; this value is shown in many instances in the 17th and 18th centuries by the spelling with z, as Zanthian, zebeck, Zerez, and instances are not uncommon in the 19th century of zantho- and zylo- for xantho- and xylo-; early examples are Zanctus Xanthus (Lydg. Troy Bk. ii. 731 rubric, 15th cent.), zyphe xiph n. (1572). Cf. Santippa Xanthippe (Chaucer), Cerses Xerxes (Wyntoun Chron., S.T.S., III. 54). A similar reduction of x took place in French:x, if he be the fyrste letter of a worde, as xenotróphe, xylobalsóme, whiche they sounde but s, sayenge senotrophe, sylobalsome, for they can nat gyve x, whiche is also a greke letter, is true sownde. (Palsgr. Esclarc. (1530) i. xxv.)