He castigated himself for being so stupid.

他责怪自己太笨。

《牛津词典》

He'll manage—he isn't stupid.

他可以的—他不笨。

《牛津词典》

He was not stupid, just lazy.

他不笨，只是懒。

youdao

At other times, he would make simple mistakes that made him appear stupid.

VOA: special.2009.05.24

Now think of it: if Milton had been the servant, he wouldn't even have made it to the stage of burying the stupid coin in the earth.

想想吧：如果弥尔顿是哪个仆人，他甚至,不会去把金币埋起来。

耶鲁公开课 - 弥尔顿课程节选

Why did God place the stupid fruit in the garden in the first place if he knew in advance that Adam and Eve were going to eat the thing?

如果他事先就知道偷食禁果的事情会发生,为什么还要把这个不祥的果实就那么放在园子里？

耶鲁公开课 - 弥尔顿课程节选

He is not stupid, he knows that some clubs will try to get around that.

BBC: Reds query Man City-Etihad deal

He looked stupid at first, because the Nasdaq then proceeded to leap to its all-time high, before later plunging in early 2000.

FORBES: Internet Bubble or Internet Boom? Yes.

Andy Hutchinson, defending, said his client accepted that he had been stupid in doing what he did and had admitted it immediately.

BBC: Ched Evans Twitter case: Mark Sweetman fined over photo