Simpleton

Origin

simple + -ton (as in a surname). Abbreviation of simple Tony or Anthony (Grose 1811 Dictionary). Compare French simplet, Italian semplicione.

Full definition of simpleton

Noun

1. (pejorative) A simple person lacking common sense.
• 2012, May 15, Scott Tobias, Film: Reviews: The Dictator, Baron Cohen’s new creation (and the previous ones, too) has its roots in Groucho characters like Captain Jeffrey T. Spaulding, Otis B. Driftwood, and Prof. Quincy Adams Wagstaff, and the concept of a pompous simpleton running a rogue nation has obvious parallels to Duck Soup’s Rufus T. Firefly, who leads the country of Fredonia to a needless and highly preventable war.
• 2001 — Eoin Colfer, Artemis Fowl, p 92The stranger had crossed a sacred line. He had mentioned the men's mothers. Nothing could get him out of a beating now, even the fact that he was obviously a simpleton. Albeit a simpleton with a good vocabulary.