Xi (letter) dialects of most of the Greek mainland and Euboea, the sound [ks] was represented by Χ (which in classical Greek is chi, used for ). Because this variant of the Greek alphabet was used in Italy, the Latin alphabet borrowed Χ rather than Ξ as the Latin letter X. While having no Latin derivative, the Xi was adopted into the early Cyrillic alphabet, as the letter ksi (Ѯ, ѯ). The uppercase letter Ξ is used as symbol for: The lowercase letter ξ is used as a symbol for: These characters are used only as mathematical symbols. Stylized Greek text should
Greek alphabet neighboring (but otherwise "red") alphabet of Euboia: a form of that resembled a Latin "L" () and a form of that resembled a Latin "S" (). <nowiki>*</nowiki>Upsilon is also derived from waw (). The classical twenty-four-letter alphabet that is now used to represent the Greek language was originally the local alphabet of Ionia. By the late fifth century BC, it was commonly used by many Athenians. In 403 BC, at the suggestion of the archon Eucleides, the Athenian Assembly formally abandoned the Old Attic alphabet and adopted the Ionian alphabet as part of the democratic reforms after the overthrow of