*idiotism*

n. [ F. idiotisme, L. idiotismus the way of fashion of a private person, the common or vulgar manner of speaking, Gr. &unr_;, fr. &unr_; to put into or use common language, fr. &unr_;. See Idiot. ] 1. An idiom; a form, mode of expression, or signification, peculiar to a language. [ 1913 Webster ]

Scholars sometimes give terminations and idiotisms, suitable to their native language, unto words newly invented. M. Hale. [ 1913 Webster ]

2. Lack of knowledge or mental capacity; idiocy; foolishness. [ 1913 Webster ]

Worse than mere ignorance or idiotism. Shaftesbury. [ 1913 Webster ]

The running that adventure is the greatist idiotism. Hammond. [ 1913 Webster ]