Xi (letter) Xi (letter) Xi (uppercase Ξ, lowercase ξ; ) is the 14th letter of the Greek alphabet. It is pronounced in Modern Greek, and generally or in English. In the system of Greek numerals, it has a value of 60. Xi was derived from the Phoenician letter samekh . Xi is not to be confused with the letter chi, which gave its form to the Latin letter X. Both in classical Ancient Greek and in Modern Greek, the letter Ξ represents the sound . In some archaic local variants of the Greek alphabet, this letter was missing. Instead, especially in the
History of the alphabet the early western Greek dialects, where the letter eta remained an , gave rise to the Old Italic alphabet which in turn developed into the Old Roman alphabet. In the eastern Greek dialects, which did not have an /h/, eta stood for a vowel, and remains a vowel in modern Greek and all other alphabets derived from the eastern variants: Glagolitic, Cyrillic, Armenian, Gothic (which used both Greek and Roman letters), and perhaps Georgian. Although this description presents the evolution of scripts in a linear fashion, this is a simplification. For example, the Manchu alphabet, descended from the abjads of