Iotacism
Iotacism (Greek: ἰωτακισμός, iotakismos) or itacism is the process of vowel shift by which a number of vowels and diphthongs converged towards the pronunciation [i] in post-classical Greek and Modern Greek. The term "iotacism" refers to the letter iota, the original sign for [i], with which these vowels came to merge.