X (letter)
X, x is a letter of the Latin alphabet. It is the twenty-fourth letter of most variants of the Latin alphabet, being placed after W and before Y: for instance it is the case in the English alphabet. Its English name is pronounced [ˈeks], like the prefix ex-.
X is also the Roman numeral representing the number 10.
Use in English
x, except when beginning a word, where it sounds like z or sh, combines the sound of k (kíng) and hissing s (síng): láx lazy sounds exactly like lácks hasn’t.
Examples (the accents show stress and pronunciation: see English phonemes): bóx, fáx, áxe, éx-, México, cóxswain (which can also be pronounced like the surname Cóxon), éxcellent, síx, sáx, táx, Réx, fóx, fóxy, tóxic, máximum, exámine, Máx, Báx, wáx, Róxy.
Some AmE speakers prefer to pronounce it [gz], at least in words beginning ex- (but not including the prefix éx- former, where it would sound inappropriately like éggs): exáct, exámine, exàmple.
Before -io- it sounds like 'ksh', [kʃ]: nóxious, ánxious, compléxion.
Often it is followed by a redundant c: excépt, éxcise, excîte, éxcellent, although if followed by a back vowel (a, o, u) the c is pronounced k: éxcavate, AmE excŏriate BrE excóriate, exhónerate (-xó-). Words with unstressed ex- can sound as if they begin éx- or íx-, according to the speaker.
But this x sound can also be written, before a front vowel, cc: áccident, not *áxident, áccent, áccess, accépt, Occidéntal, cóccyx *kóxix.
x is of course itself a consonant cluster, and it begins the following accidental ones: xb, xcl, xl, xm, xt: óxbow, exclâim, áxle, Áxminster, extól.
Final nx is pronounced '-ngks', [ŋks]: lýnx, mínx, Sphínx, jínx. The pronunciation of ánxious is *ángshəss or *ánkshəss, while anxîety is pronounced *angzîety.
Initial x is rare. In words from Greek it sounds like z: xylophone, Xénophon, xénophobe. This can be seen in the two differing x’s in Xërxês (*Zërxêez). It can also be initial, as well as medial, in Chinese names, where it always sounds like sh: Xinjiáng.
x also sounds like z in French plurals: tábleaux (*táblôz), pláteaux (*plátôz).
There is a silent French x in faux-pàs (*fô-pà).
xx is purely commercial: Éxxon, Bób B. Sóxx (a respelling of bóbby sócks).