|Writing system||Latin script|
|Type||Alphabetic and Logographic|
|Language of origin||Latin language|
|Time period||~-700 to present|
|Descendants|| • ×|
|Other letters commonly used with||x(x)|
X, or x, is the twenty-fourth and third-to-last letter in the modern English alphabet and the ISO basic Latin alphabet. Its name in English is "ex" (pronounced //), plural exes. X is regularly pronounced as "ks".
In Ancient Greek, 'Χ' and 'Ψ' were among several variants of the same letter, used originally for /kʰ/ and later, in western areas such as Arcadia, as a simplification of the digraph 'ΧΣ' for /ks/. In the end, more conservative eastern forms became the standard of Classical Greek, and thus 'Χ' (Chi) stood for /kʰ/ (later /x/; palatalized to [ç] in Modern Greek before front vowels). However, the Etruscans had taken over 'Χ' from western Greek, and it therefore stands for /ks/ in Etruscan and Latin.
The letter 'Χ' ~ 'Ψ' for /kʰ/ was a Greek addition to the alphabet, placed after the Semitic letters along with phi 'Φ' for /pʰ/.
|/ʃ/||Usually (word-initially, after consonants, i, au, eu, in some surnames such as Rexach)|
|Mandarin Chinese||Standard Mandarin||/ɕ/||In Pinyin latinization|
|Cou||/ɨ/ ~ /ʉ/||Possibly the only case in the world of <x> used as a vowel.|
|Dutch||/ks/||Usually||Letter mainly used in loanwords|
|English||/gz/||Before a stressed vowel|
|/gʒ/||Only in luxury and derivatives|
|/h/||Don Quixote, Oaxaca, words derived from Classical Nahuatl/Nahuatl|
|/ks/||Usually; before an unstressed vowel|
|/kʃ/||Groups -xion(-), -xious(-), -xua-; in the word flexure|
|Esperanto||in digraphs only||cx, gx, hx, jx, sx, ux are used as substitutes for ĉ, ĝ, ĥ, ĵ, ŝ, ŭ where these characters are not available.||See X-convention|
|French||/gz/||Mainly in the prefix ex- followed by a vowel; sometimes word-initially|
|/ks/||Usually; in Aix- (prefix or name of several places)|
|/s/||In six (6), dix (10), Auxerre, and Bruxelles (Brussels)|
|silent||Word-finally with no liaison|
|/z/||Word-finally with liaison; in sixième (6th) and dixième (10th)|
|Galician||/(k)s/||Some words||In learned loanwords|
|German||/ks/||Letter mainly used in loanwords|
|Indonesian||/s/||In the beginning of a word||Mainly used in loanwords for science|
|/ks/||In the middle or the end of a word, although words borrowed with the letter x in the middle or the end of a word are always replaced by the letters 'ks'. For example, the word 'maximum' and 'climax' in Indonesian would be 'maksimal' and 'klimaks'. Letter x on the middle or the end of a word only occurs in names.|
|Italian||/ks/||Letter mainly used in learned loanwords|
|Portuguese||/gz/||In the prefix hexa- ("hexa-")|
|/ks/||Some words||Mainly in learned loanwords|
|/s/||When preceded by <e> and a consonant; some words|
|/ʃ/||Word-initially; in words derived from Tupi; usually|
|/z/||In the prefix ex- ("ex-") before a vowel|
|Sicilian||/ʃ/||Pronunciation for Old Sicilian words||See e.g. Craxi, Joppolo Giancaxio|
|/k(ə)s(ə)/||Pronunciations for loanwords|
|/(t)ʃ/||In some names and words|
|Venetian||/s/||In Venexia "Venice"|
In English orthography, ⟨x⟩ is typically pronounced as the voiceless consonant cluster // when it follows the stressed vowel (e.g. ox), and the voiced consonant // when it precedes the stressed vowel (e.g. exam). It is also pronounced // when it precedes a silent ⟨h⟩ and a stressed vowel (e.g. exhaust). Before ⟨a⟩, ⟨i⟩ or ⟨u⟩, it can be pronounced // or // (e.g. sexual and luxury); these result from earlier // and //. It also makes the sound // in words ending in -xion (except for axion). When ⟨x⟩ ends a word, it is always // (e.g. fax), except in loan words such as faux (see French, below).
There are very few English words that start with ⟨x⟩ (the fewest of any letter). When ⟨x⟩ does start a word, it is usually pronounced 'z' (e.g. xylophone, xenophobia, and xanthan). When starting in some names or as its own representation it is pronounced 'eks', in rare recent loanwords or foreign proper names, it can also be pronounced // (e.g. the obsolete Vietnamese monetary unit xu) or // (e.g. Chinese names starting with Xi like Xiaomi or Xinjiang). Many of the words that start with ⟨x⟩ are of Greek origin, or standardized trademarks (Xerox) or acronyms (XC). In abbreviations, it can represent "trans-" (e.g. XMIT for transmit, XFER for transfer), "cross-" (e.g. X-ing for crossing, XREF for cross-reference), "Christ-" (e.g. Xmas for Christmas, Xian for Christian), the "crys-" in crystal (XTAL), or various words starting with "ex-" (e.g. XL for extra large, XOR for exclusive-or).
X is the third least frequently used letter in English (after ⟨q⟩ and ⟨z⟩), with a frequency of about 0.15% in words.
In Latin, ⟨x⟩ stood for [ks]. In some languages, as a result of assorted phonetic changes, handwriting adaptations or simply spelling convention, ⟨x⟩ has other pronunciations:
Additionally, in languages for which the Latin alphabet has been adapted only recently, ⟨x⟩ has been used for various sounds, in some cases inspired by European usage, but in others, for consonants uncommon in Europe. For these no Latin letter stands out as an obvious choice, and since most of the various European pronunciations of ⟨x⟩ can be written by other means, the letter becomes available for more unusual sounds.
In the International Phonetic Alphabet, ⟨x⟩ represents a voiceless velar fricative.
In mathematics, x is commonly used as the name for an independent variable or unknown value. The modern tradition of using x, y and z to represent an unknown (incognita) was introduced by René Descartes in La Géométrie (1637). As a result of its use in algebra, X is often used to represent unknowns in other circumstances (e.g. X-rays, Generation X, The X-Files, and The Man from Planet X; see also Malcolm X).
On some identification documents, the letter X represents a non-binary gender, where F means female and M means male.
In the Cartesian coordinate system, x is used to refer to the horizontal axis.
It is also sometimes used as a typographic approximation for the multiplication sign, ), partly to avoid confusion with the multiplication symbol. In fonts containing both x (the letter) and × (the multiplication sign), the two glyphs are dissimilar.. In mathematical typesetting, x meaning an algebraic variable is normally in italic type (
It can be used as an abbreviation for 'between' in the context of historical dating; e.g., '1483 x 1485'.
Maps and other images sometimes use an X to label a specific location, leading to the expression "X marks the spot".
The Roman numeral X represents the number 10.
In art or fashion, the use of X indicates a collaboration by two or more artists, e.g. Aaron Koblin x Takashi Kawashima. This application, which originated in Japan, now extends to other kinds of collaboration outside the art world. This usage mimics the use of a similar mark in denoting botanical hybrids, for which scientifically the multiplication × is used, but informally a lowercase "x" is also used.
In text language, at the end of a letter or at the end of an email 'x' can mean a kiss.
An X rating denotes media such as movies that are intended for adults only.
|Unicode name||LATIN CAPITAL LETTER X||LATIN SMALL LETTER X|
|Numeric character reference||X
In the C programming language, "x" preceded by zero (as in 0x or 0X) is used to denote hexadecimal literal values.
X is commonly used as a prefix term in nouns related to the X Window System and Unix.
In the course of time, I, V and X became identical with three letters of the alphabet; originally, however, they bore no relation to these letters.