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. M. Hale.
2. Lack of knowledge or mental capacity; idiocy; foolishness.
Worse than mere ignorance or idiotism. Shaftesbury.
The running that adventure is the greatist idiotism. Hammond.