Ĭdĭ-ot-īsm, n.

n. [Fr. idiotisme, It. & Sp. idiotismo, Lat. idiotismus, Gr. ιδιωτισμός, the way or fashion of a private person, the common or vulgar manner of speaking, from ιδιωτίζειν, to put into or use common language, &c., from ιδιώτης. See IDIOT.] 1. An idiom; a mode of expression peculiar to a language. Scholars sometimes give terminations and idiotisms, suitable to their native language, to words newly invented. [Obs.] Hale. 2. Lack of knowledge or mental capacity; idiocy; foolishness. [Obs.] “Somewhat worse than mere ignorance or idiotism.” Shaftesbury.