Chi (letter) for the design of steel structures. In graph theory, a lowercase chi is used to represent a graph's chromatic number. Chi (letter) Chi (uppercase Χ, lowercase χ; ) is the 22nd letter of the Greek alphabet, pronounced or in English. Its value in Ancient Greek was an aspirated velar stop (in the Western Greek alphabet: /ks/). In Koine Greek and later dialects it became a fricative (/) along with Θ and Φ. In Modern Greek, it has two distinct pronunciations: In front of high or front vowels ( or ) it is pronounced as a voiceless palatal fricative , as
History of the Greek alphabet the Latin alphabet. Most specialists believe that the Phoenician alphabet was adopted for Greek during the early 8th century BC, perhaps in Euboea. The earliest known fragmentary Greek inscriptions date from this time, 770–750 BC, and they match Phoenician letter forms of c. 800–750 BC. The oldest substantial texts known to date are the Dipylon inscription and the text on the so-called Cup of Nestor, both dated to the late 8th century BC, inscriptions of personal ownership and dedications to a god. Tradition recounts that a daughter of a certain Agamemnon, king of Aeolian Cyme, married a Phrygian king called