A blunder or clumsy mistake caused by carelessness or awkwardness; also used to describe someone as clumsy ('a klutz').
彼はよくドジを踏むが、憎めない人だ。
He often makes blunders, but he's endearing.
急いでいてドジをして、財布を忘れてきた。
I was in a hurry and made a careless mistake — I forgot my wallet.
ドジなところがあるけれど、一生懸命働く。
He has clumsy moments, but he works hard.