頭が悪い

stupid

→ 頭
phrase Rare #38,156
stupid Literally, “the head is bad.” This is a blunt, potentially insulting way to describe someone as unintelligent.
JA: そんなことをするなんて、頭が悪いね。
EN: Doing something like that is stupid.

頭が悪いばかりか生意気だそれに恥知らずだ

Not only are you stupid, but you're also insolent—and shameless to boot.

— 大人は判ってくれない (1959)

ただ単に頭が悪いだけじゃねえのか~?

Could it just be that you're stupid?

— AKIRA (1988)

ここだけの話だが、彼はだいぶ頭が悪いと思うよ。

Between you and me, I think he's pretty stupid.

彼女は決して頭が悪い人じゃない。

She’s not stupid at all.

頭が悪いね、君。

You're stupid, you know.