na-adjective, noun
disadvantageous; harmful; unprofitable
Describes a situation, action, or outcome that is unfavorable, detrimental, or not beneficial. Often used in formal or written contexts.
その契約は我々にとって不為だ。
That contract is disadvantageous for us.
不為な条件を受け入れるわけにはいかない。
We cannot accept harmful conditions.