X

'X' is the twenty-fourth letter in the modern Latin alphabet. Its name in English is pronounced ''eks'' ().
In phonetics, ''x'' is the IPA and X-SAMPA symbol for the voiceless velar fricative (IPA is used for pronunciation throughout this article).

Contents

History

Usage

Codes for computing

See also

Other uses for the letter X

History

The consonant cluster was, in Ancient Greek, written as either ''Chi'' 'Χ' (Western Greek) or ''Xi'' 'Ξ' (Eastern Greek). In the end, ''Chi'' was standardized as ( in Modern Greek), while ''Xi'' was standardized for . But the Etruscans had taken over ''Χ'' from older Western Greek; therefore, it stood for in Etruscan and Latin.
It is unknown whether the letters ''Chi'' and ''Xi'' are Greek inventions, or whether they are ultimately of Semitic origin. ''Chi'' was placed toward the end of the Greek alphabet, after the Semitic letters, along with ''Phi'', ''Psi'', and ''Omega'', suggesting that it was an innovation; further, there is no letter corresponding specifically to the sound /ks/ in Semitic. There was a Phoenician letter ''kheth'' with a probable sound , somewhat similar to , but this was adopted into Greek as first the consonant /h/, and later, the long vowel ''Eta'' (Η,η), and does not seem to have been the source of Greek ''Chi''. The Phoenician letter ''Samekh'' (representing /s/) is usually considered the inspiration for Greek ''Xi'', but as noted, ''Chi'' had a graphically distinct shape from ''Xi'' — although it may possibly have been another variant originally based on ''samekh''. The original form of ''samekh'' may have been an Egyptian hieroglyph for the Djed column, but this too is uncertain, as no intervening Proto-Sinaitic form of this letter is attested.

Egyptian hieroglyph "column"	Phoenician S	Greek Xi	Greek Chi	Etruscan X
R11	PhoenicianX-01.png			EtruscanX-01.png

Usage

In some languages, as a result of assorted phonetic changes and handwriting adaptations, ''X'' has other pronunciations:

★ Basque: as a spelling for [ʃ].

★ English: ''X'' is a double consonant or, rather, a sign for the compound consonants ; or sometimes when followed by an accented syllable beginning with a vowel, or when followed by silent h and an accented vowel (e.g. ''exhaust'', ''exam''); usually at the beginnings of words (e.g. ''xylophone''), and in some compounds keeps the sound, as in (e.g. ''meta-xylene''). It also makes the sound in words ending in -xion (typically used only in British-based spellings of the language; American spellings tend to use -ction). It can also represent the sounds or , for example, in the words luxury and sexual, respectively. When the letter ''X'' begins a word in the English language such as ''xynene'' and a ''z'' sound is created the ''X'' is said to be silent. Final x is always (e.g. ''ax''/''axe'') except in loan words such as ''faux'' (see French, below).

★ French: at the ends of words, silent (or in liaison if the next word starts with a vowel). This usage arose as a handwriting alteration of final ''-us''. Two exceptions are pronounced [s]: ''six'' and ''dix''.

★ In Norwegian, ''X'' is generally pronounced , but since the nineteenth century there has been a tendency to spell it out as ''ks'' whenever possible; it may still be retained in names of people, though it is fairly rare, and occurs mostly in foreign words and SMS language.

★ Spanish: In Old Spanish, ''X'' was pronounced like as it is still currently in other Iberian languages. Later, the sound evolved to a hard sound. In modern Spanish, the hard sound is spelled with a ''j'', or with a ''g'' before ''e'' and ''i'', though ''x'' is still retained for some names (notably ''México'', which alternates with ''Méjico''). Now, ''X'' represents the sound (word-initially), or the consonat clusters and (e.g. ''oxígeno'', ''examen''). Even rarer; like in Old Spanish, the ''x'' can be pronounced as in modern day in some proper nouns such as ''Raxel'' (a variant of Rachel) and ''Xelajú''. In American and seseo Spanish, the ''xc'' in ''excelente'' is pronounced as but in Spain, this combination is pronounced .

★ In Albanian, ''x'' represents , while the digraph ''xh'' represents .

★ Polish doesn't use ''X''. In loanwords, ''X'' is either replaced by ''ks'' like in 'ekstra' (extra), or ''gz'' like in 'egzotyczny' (exotic).

★ Nguni languages: represents the Lateral alveolar click .

★ In some recently created alphabets based on the Roman alphabet, ''x'' represents . This is the case in Kurdish, Azerbaijani, Uzbek, Tatar and Lojban.

★ In Hanyu Pinyin, the official transcription system for Mandarin Chinese, the letter ''x'' denotes the voiceless alveolo-palatal fricative .

★ In the German and Italian languages, ''X'' is used mainly in foreign loan words.

★ In Maltese x is pronounced
No words in the Basic English vocabulary begin with ''X'', but it occurs in words beginning with other letters. It is often found in a word with an E before it. Otherwise it is the third most rarely used letter in the English language.

Codes for computing

In Unicode the capital X is codepoint U+0058 and the lowercase x is U+0078.
The ASCII code for capital X is 88 and for lowercase x is 120; or in binary 01011000 and 01111000, correspondingly.
The EBCDIC code for capital X is 231 and for lowercase x is 167.
The numeric character references in HTML and XML are "X" and "x" for upper and lower case respectively.

See also

For other uses and meanings of the letter "X", see X (disambiguation). See also:

★ Ex

★ XXXX

★ XXX

★ XX

★ Rx

★ Tx
Similar non-Latin letters:

★ Χ : Greek letter Chi

★ Х : Cyrillic Kha

★ メ : Me (Japanese katakana character)

★ א (Hebrew aleph) sometimes looks like X when handwritten.

★ 乂 : A Japanese or Chinese character usually used in names, pronounced as "Ai".

★ In pre-Norman Britain a "ᚷ" (Gyfu) was a letter in the Anglo-Saxon Futhorc runic alpabet and also indicated a gift.
Unicode has also several similar non-letter symbols:

★ × : multiplication sign

★ ╳ : box drawings left diagonal cross

★ : multiplication x

★ : ballot x

★ : heavy ballot x

★ × : vector or cross product

Other uses for the letter X

★ A colloquial name for the drug MDMA (derived from another nickname ectasy or XTC)

★ A placeholder or modifier in usernames (e.g. MagmaX or ixamxthexmaster)

★ In genetics, the X chromosome

★ A strike in baseball or bowling

★ Denotes infantry on military maps

★ Marks a mountain summit on topographic maps, such as printed by the USGS

★ Slang, a kiss, as in "XOXO"

★ In American football schematics, a member of the defensive squad

★ In ASCII_tab, a muted or unplayed guitar string

★ In musical notation, a double sharp, raising a note by one full step

★ In electronic circuit diagrams, an unused pin of a chip, or, in a circle, a lamp

★ Short for "cross", including such abbreviations as "lax" for "lacrosse", or "x-country" for "cross country"

★ The roman numeral for ten, X

★ Marks the spot, as on a map of buried treasure

★ Experimental, as in X-plane (aircraft)

★ Christ, as in Xmas

★ In older movie ratings, denoted films to which viewers younger than 18 were not admitted.

★ In the ''Devil's Dictionary'' by Ambrose Bierce, appears this entry: "In the algebra of psychology, ''X'' stands for woman's mind."