Eta

In the southern Italian colonies of Heracleia and Tarentum, the letter shape was reduced to a "half-heta" lacking the right vertical stem (Ͱ).

"[3] In the East Ionic dialect, however, the sound [h] disappeared by the sixth century BC, and the letter was re-used initially to represent a development of a long open front unrounded vowel, [aː], which later merged in East Ionic with the long open-mid front unrounded vowel, [ɛː] instead.

Itacism is continued into Modern Greek, where the letter name is pronounced [ˈita] and represents the close front unrounded vowel, [i].

In Modern Greek, due to iotacism, the letter (pronounced [ˈita]) represents a close front unrounded vowel, [i].

In information theory the uppercase Greek letter Η is used to represent the concept of entropy of a discrete random variable.