nitwit

don't be such a nitwit; think before you act.

he called me a nitwit for forgetting his birthday.

sometimes i feel like a nitwit for making the same mistake.

she laughed at him, saying he was a nitwit for not studying.

it's a nitwit move to ignore the advice of experts.

he may be a nitwit, but he's got a good heart.

don't be a nitwit; just follow the instructions carefully.

she felt like a nitwit for not understanding the joke.

calling him a nitwit was uncalled for; he was just confused.

he realized he had been a nitwit for not taking the opportunity.