Eta

Eta /ˈiːtə, ˈeɪtə/ EE-tə, AY-tə (uppercase Η, lowercase η; Ancient Greek: ἦτα ē̂ta [ɛ̂ːta] or Greek: ήτα ita [ˈita]) is the seventh letter of the Greek alphabet, representing the close front unrounded vowel, [i]. Originally denoting the voiceless glottal fricative, [h], in most dialects of Ancient Greek, its sound value in the classical Attic dialect was a long open-mid front unrounded vowel, [ɛː], which was raised to [i] in Hellenistic Greek, a process known as iotacism or itacism.

In the ancient Attic number system (Herodianic or acrophonic numbers), the number 100 was represented by "Η", because it was the initial of ΗΕΚΑΤΟΝ, the ancient spelling of ἑκατόν = "one hundred". In the later system of (Classical) Greek numerals eta represents 8.

Eta was derived from the Phoenician letter heth . Letters that arose from eta include the Latin H and the Cyrillic letters И and Й.