nitwit

First attested in the 1910s in the US Northeast. Likely from German nit, dialect form of nichts (“nothing”), or Yiddish ניט (nit), dialect form of נישט (nisht, “no”), although some dictionaries give the alternative etymology nit (“louse egg; something very small”) + wit.

出典: Wiktionary「nitwit」（CC BY-SA 4.0）