How to say "half-wit" in Japanese

• うすのろ
  noun, na-adjectiveCovers 'half-wit' as a simpleton, someone slow-witted and dull. A mild, contemptuous way to call a person a fool, usually written in kana alone; it is less common than 間抜け.
• 間抜けまぬけCommon
  nounCovers 'half-wit' in the general sense of a fool or blockhead, someone lacking sense. A common everyday insult for a silly or dim-witted person, and the usual word to reach for here.
  あいつはクラスでいちばんのまぬけだ。↗

  He is the dumbest kid in the class.

For 'half-wit' as an insult meaning a stupid or dim-witted person, 「間抜け」 is the common everyday choice; 「うすのろ」 also means a dull, slow-witted fool but is less commonly used.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• うすのろhalf-wit
• 間抜けまぬけfool