Lewis & Short

barbărŏlexis, eos, f., = βαρβαρόλεξις, the perversion of the form of a word, esp. the change or in flection of a Greek word according to Latin usage (while barbarismus is the erroneous pronunciation of a Latin word), Isid. Orig. 1, 31, 2 (in Charis. p. 237 P. used as Greek).