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
Latin alphabet Hyginus in "Fab. 277" mentions the legend that it was Carmenta, the Cimmerian Sibyl, who altered fifteen letters of the Greek alphabet to become the Latin alphabet, which her son Evander introduced into Latium, supposedly 60 years before the Trojan War, but there is no historically sound basis to this tale.) The Ancient Greek alphabet was in turn based upon the Phoenician abjad. From the Cumae alphabet, the Etruscan alphabet was derived and the Romans eventually adopted 21 of the original 27 Etruscan letters: Latin included 21 different characters. The letter was the western form of the Greek gamma, but