simpleton

This term carries a strong derogatory connotation, suggesting a lack of mental acuity or a naive nature that makes a person vulnerable to manipulation. It evokes an image of someone who is not merely unintelligent, but specifically gullible and lacking in worldly wisdom. While it can be used as a harsh insult, it sometimes appears in folklore or literary archetypes to describe a character whose perceived foolishness is contrasted with an unexpected purity of heart or accidental success.