iotacism

noun
io·​ta·​cism | \ ī-ˈōt-ə-ˌsiz-əm How to pronounce iotacism (audio) \

Medical Definition of iotacism

1 : a speech defect marked by use of the sound \ē\ in place of other vowel sounds
2 : a speech defect marked by inability to correctly pronounce the sound \ē\