idiotism noun4 •(historical) Very severe mental retardation.He did not perceive that regal power, in a few generations, introduces idiotism into the noble stem […] — 1791 •A foolish utterance.[…] that clear soprano, in nursery, rings out a shower of innocent idiotisms over the half-stripped baby, and suspends the bawl upon its lips. — 1863 •Idiom. •An overly literal translation of an idiom. formsidiotisms
