dunderhead

dated

(somewhat dated) A stupid person; a dunce.

Japanese Meaning

愚か者、馬鹿、阿呆

Don't be such a dunderhead — read the instructions before you start the machine.

そんなまぬけな人にならないで、機械を動かす前に取扱説明書を読んでください。

Sense（1）

(somewhat dated) A stupid person; a dunce.

You're the stupidest dunderhead I ever saw or ever heard of, so help me Moses!

dunderheads

（ plural ）