Eta (uppercase Η, lowercase η; Greek: Ήτα Hēta) is the seventh letter of the Greek alphabet. Originally denoting a consonant /h/, its sound value in the classical Attic dialect of Ancient Greek was a long vowel [ɛː], raised to [i] in medieval Greek, a process known as iotacism.In the system of Greek numerals it has a value of 8. It was derived from the Phoenician letter heth 20px. Letters that arose from Eta include the Latin H and the Cyrillic letter И.