idiot

Etymology

Recorded from the early 14th century.^[1] From Middle English idiote (“ignorant person”),^[2][3] borrowed from Old French idiote (“uneducated or ignorant person”),^[1][2] from Latin idiōta (“ordinary person, layman”),^[1][4] from Ancient Greek ἰδιώτης (idiṓtēs, “private person, layman”),^[2][4] from ídios “one's own, private”.^[2][5]

The Greek word meant a private person as opposed to one taking part in public affairs, and was also used patronizingly for an ignorant person.^[1] Compare idiom.^[1]

References

1. [1] [2] [3] [4] [5] Harper, Douglas, Online Etymology Dictionary, https://www.etymonline.com
2. [1] [2] [3] [4] The American Heritage Dictionary of the English Language, Boston: Houghton Mifflin
3. [1] Wiktionary, the free dictionary, https://en.wiktionary.org
4. [1] [2] Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
5. [1] Merriam-Webster's Collegiate Dictionary, Springfield, Mass.: Merriam-Webster