simpleton

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

• IPA^(key): /ˈsɪmpəltən/

simpleton (plural simpletons)

1. (derogatory) A simple-minded person lacking common sense.
   • 2012 May 15, Scott Tobias, “Film: Reviews: The Dictator”, in The Onion AV Club‎:

     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 92

     The 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.

• simpleton on Wikipedia.Wikipedia