Id"i*ot*ism (?), n. [F. idiotisme, L. idiotismus the way of fashion of a private person, the common or vulgar manner of speaking, Gr. &?;, fr. &?; to put into or use common language, fr. &?;. See Idiot.] 1. An idiom; a form, mode of expression, or signification, peculiar to a language.

Scholars sometimes give terminations and idiotisms, suitable to their native language, unto words newly invented.

2. Lack of knowledge or mental capacity; idiocy; foolishness.

Worse than mere ignorance or idiotism.

The running that adventure is the greatist idiotism.