simpleton

/ˈsɪmpəltən/
noun
  1. A person who is not very intelligent or who lacks common sense; a fool.
    • He felt like a simpleton when he couldn't figure out the simple puzzle.
    • The villain in the story was a simpleton who always fell for the hero's tricks.
    • Don't be such a simpleton—you can't believe everything you read online.
Antonyms
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