X

X is the twenty-fourth letter of the Latin alphabet. It is also the form of St Andrew's Cross. /ks/ was in Ancient Greece written as Chi 'Χ' (Western Greek) or Xi 'Ξ' (Eastern Greek). In the end, Chi was standardized as /k_h/ (/x/ in Modern Greek) as well as Xi for /ks/. But the Etruscans took over X from older Western Greek, therefore, it stood for /ks/ in Etruscan and /ks/ and /gs/ [gz] in Latin. Only in Kurdish, Azeri, Uzbek and Tatar as well as the IPA and SAMPA (the latter is used here) is X pronounced [x] (as in German Bach). Some scholars claim that Latin X is not identical with Greek X. It is also controversial whether Psi, Chi (Khi) and Xi are Greek inventions or whether they are ultimately of Semitic origin. X-ray represents the letter X in the NATO phonetic alphabet.

Meanings for X

\n* In a general sense, X represents the unknown or secret, as in project X and in the context of X rays, a form of electromagnetic radiation. Planet X is a hypothetical additional planet farther from the sun. Members of the Nation of Islam change their surnames to "X" to symbolize that their African names were lost in slavery, an example is Malcolm X.\n* In art X alludes to the infinite joy of creation.\n* In beverages, X is a symbol for an alcoholic proof of 50; multiple Xes indicate multiples of 50.\n* In cabalistic philosophy X references both birth and death.\n* In clothing X is used as an abbreviation for extra, such as XXL for extra-extra-large.\n* In computing, X is the name of a free graphical windowing system developed at MIT and standard on Unix and Linux; see X Window System.\n* In education, X is a nickname for the École polytechnique.\n* In electrical engineering, X is the symbol for reactance.\n* In English, \n**X is an abbreviation for Christ, as in Xmas (Christmas) and Xtian (Christian).\n**X is an symbol for a kiss, as in love notes.\n**X is an abbreviation for cross in words like Xing (crossing), or to sign with a cross (often for illiteracy). \n**X is slang for Ecstacy, the drug MDMA.\n**X also serves as other abbreviations, such as Xtal (Crystal), reXn (reaction) and Xperimental (experimental).\n* In film\n** X is a rating given to films suitable for an adult-only audience; see X-rated. NC-17 has replaced the X rating in the US. The UK replaced the X rating with the 18 certificate. Australia retains the X rating.\n** X is the name of a 1928 German film; see X (film)\n* In financial securities, X is the stock symbol for United States Steel Corporation. \n* In games, X is represention for a cross in games like tic tac toe\n* In genetics X denotes the X chromosome.\n* In mathematics, x commonly represents an unknown variable. Even though any letter can be used, x is the most common by far. This usage can be traced back to the Arabic word ?ay 'thing' which was spelled with an initial x in Old Spanish or (according to other sources) an abbreviation of Latin causa which was the translation of Arabic š.\n* In military science, X is the US Navy hull classification symbol for Submersible Craft.\n* In popular music,\n** X is the name of a Los Angeles punk rock band (see X (US band)).\n** X is the name of an Australian punk rock band (see X (Australian band)).\n* In photography X denotes exact time in flash synchronization.\n* In pornography XXX relates, unsurprisingly, to sex.\n* In U.S politics, X is the pseudonym of the person who blew the whistle on the Watergate crisis.\n* In U.S public policy, X is the author (George F. Kennan) of the X article published in Foreign Affairs.\n* In Roman numerals, X denotes ten.\n* In semiotics, an X over something denotes elimination, prohibition or erasure.\n* In sociology X denotes Generation X.\n* In treasure-hunting X is used to designate the location of treasure, i.e. X marks the spot.\n* X is the title of an anime based on the manga X/1999. See X (anime). Two-letter combinations starting with X:\n*xa xb xc xd xe xf xg xh xi xj xk xl xm xn xo xp xq xr xs xt xu xv xw xx xy xz \n\n\n\n\n\n\n\n\n\n\n\n\n