What does 無駄 mean?
無駄 is a Japanese noun meaning “futility, uselessness” in English. It is written as 無駄 in kanji, むだ in hiragana, and muda in romaji. This word is part of JLPT N3 vocabulary.
Example sentence
今更後悔しても無駄だ。
It's no use regretting it now.