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 Χ.
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
- In a general sense, X represents an unknown or secret, as in project X.
- 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.
- In aeronautics, X is the designation given to an experimental military aircraft before it is officially commissioned. For example, the F-35 Joint Strike Fighter was originally the X-35 during its testing phase.
- In anime, X is the title of a series based on the manga X/1999 (see X (anime)).
- In art X alludes to the infinite joy of creation.
- In astronomy, Planet X is a hypothetical planet in the Solar System beyond the orbit of Pluto.
- In beverages, X is a symbol for an alcoholic proof of 50; multiple Xes indicate multiples of 50.
- In cabalistic philosophy X references both birth and death.
- In clothing X is used as an abbreviation for extra, such as XXL for extra-extra-large.
- 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.
- In education, X is a nickname for the École Polytechnique.
- In electrical engineering, X is the symbol for reactance.
- In English,
- X is an abbreviation for Christ, as in Xmas (Christmas) and Xtian (Christian).
- X is an symbol for a kiss, as in love notes.
- X is an abbreviation for cross in words like Xing (crossing), or to sign with a cross (often for illiteracy).
- X is slang for Ecstacy, the drug MDMA.
- X also serves as other abbreviations, such as Xtal (Crystal), reXn (reaction) and Xperimental (experimental).
- In film
- 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.
- X is the name of a 1928 German film; see X (film)
- In financial securities, X is the stock symbol for United States Steel Corporation.
- In games, X is represention for a cross in games like tic tac toe (naughts and crosses)
- In genetics X denotes the X chromosome.
- 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.
- x is the usual symbol for the variable represented on the horizontal axis (ordinate) in analytic geometry.
- In military science, X is the US Navy hull classification symbol for Submersible Craft.
- In physics, the X-ray is a form of electromagnetic radiation.
- In popular music,
- In photography X denotes exact time in flash synchronization.
- In pornography XXX relates, unsurprisingly, to sex.
- In U.S. politics, X is the pseudonym of the person who blew the whistle on the Watergate crisis.
- In U.S. public policy, X is the author (George F. Kennan) of the X article published in Foreign Affairs.
- In Roman numerals, X denotes ten.
- In semiotics, an X over something denotes elimination, prohibition or erasure.
- In sociology X denotes Generation X.
- In superhero comic books, an X usually denotes a connection to the popular X-Men franchise, especially when used as a prefix.
- In treasure-hunting X is used to designate the location of treasure, i.e. X marks the spot.
- X is a rollercoaster at Six Flags Magic Mountain.
See also
Two-letter combinations starting with X:
