Synonyms for Simpleton:

n.

clown, joker, maniac, dumb blond, numpty. ability, ding-dong, dip, gander, goof, goose, jerk, nerd, ninny, schmuck, tomfool, turkey, Mooncalf, schmo, softhead. fool (noun)
birdbrain, blockhead, bonehead, buffoon, bungler, clod, clown, cretin, dimwit, dolt, dullard, dumbbell, dummy, dunce, fool, half-wit, ignoramus, imbecile, jerk, loon, moron, nincompoop, nitwit, crackpot, chuckle-head, knuckle-head, lame-brain, meathead.
ignoramus (noun)
birdbrain, buffoon, scatterbrain.
person (noun)
simple.
schmuck (noun)
schmuck.
simpleton (noun)
simple.
stupid person (noun)
clod, dolt, dumbbell, dummy, dunce.

Other synonyms:

ding-dong, nerd, ninny, schmuck, tomfool, schmo, softhead. goof, goose, turkey. gander. idiot
Mooncalf.
Other relevant words:
clown, ding-dong, dip, gander, goof, goose, jerk, nerd, ninny, schmuck, simple, tomfool, turkey, Mooncalf, schmo, softhead.

Usage examples for simpleton

  1. The little girl would then see that all in the world he cared about was to have her back, and she would tell him he was just as big a simpleton now as when she went away. – The Emperor of Portugallia by Selma Lagerlof
  2. There's not time; and I 'm a simpleton at the game. – The Complete Project Gutenberg Works of George Meredith by George Meredith
  3. If your philosophy can find no answer to the question, will you expect a hopeless simpleton to furnish one? – The Children of the World by Paul Heyse