ラテン語の idiota、無知な人、平民、ギリシャ語の idios、個人的な、自分の、語源は idiom と同じ、派生語源は孤立した人、社会の問題に参加しない人、最終的に無知な人、愚か者、バカ。
Reader, suppose you were an idiot. And suppose you were a member of Congress. But I repeat myself. [Mark Twain, c. 1882]Idiot box "television set" is from 1959; idiot light "dashboard warning signal" is attested from 1968. Idiot savant attested by 1870.