The Collaborative International Dictionary of English v.0.48:

Iotacism \I*o"ta*cism\ ([-i]*[=o]"t[.a]*s[i^]z'm), n. [Gr.
   'iotakismo`s a laying too much stress upon the iota ([iota]):
   cf. F. iotacisme. See Iota.]
   The frequent use of the sound of iota (that of English e in
   be), as among the modern Greeks; also, confusion from
   sounding [epsilon], [iota], [eta], [upsilon],
   [epsilon][iota], etc., like [iota]. --Littr['e].
   [1913 Webster] I O U