na-adjective, noun
uselessness; futility; in vain
Literary or formal word for something being pointless or without effect. Often used in the adverbial form 徒爾に (とじに) meaning 'in vain' or 'to no purpose'. Rare in everyday conversation.
彼の努力は徒爾に終わった。
His efforts ended in vain.
徒爾な議論は避けるべきだ。
We should avoid futile arguments.