Chi (letter)

Chi 'kaɪ,_"xi: (uppercase Χ, lowercase χ; χῖ) is the twenty-second letter of the Greek alphabet. Its value in Ancient Greek was an aspirated velar stop /kh/ (in the Western Greek alphabet: /ks/). In Koine Greek and later dialects it became a fricative ([x]/[ç]) along with Θ and Φ. In Modern Greek, it has two distinct pronunciations: In front of high or front vowels (/e/ or /i/) it is pronounced as a voiceless palatal fricative [ç], as in German ich or like the h in some pronunciations of the English words hew and human. In front of low or back vowels (/a/, /o/ or /u/) and consonants, it is pronounced as a voiceless velar fricative ([x]), as in German ach or Spanish j. Chi is romanized as in most systematic transliteration conventions, but sometimes is used. In addition, in Modern Greek, it is often also romanized as or in informal practice. In the system of Greek numerals, it has a value of 600. In ancient times, some local forms of the Greek alphabet used the chi instead of xi to represent the /ks/ sound. This was borrowed into the early Latin language, which led to the use of the letter X for the same sound in Latin, and many modern languages that use the Latin alphabet. Chi was also included in the Cyrillic script as the letter Х, with the phonetic value /x/ or /h/. Chi is the basis for the name literary chiastic structure and the name of chiasmus. In Plato's Timaeus, it is explained that the two bands that form the soul of the world cross each other like the letter Χ. Plato's analogy, along with several other examples of chi as a symbol occur in Thomas Browne's discourse The Garden of Cyrus (1658). Chi or X is often used to abbreviate the name Christ, as in the holiday Christmas (Xmas). When fused within a single typespace with the Greek letter rho, it is called the labarum and used to represent the person of Jesus Christ. These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style.