na-adjective, noun which may take the genitive case particle 'no', noun
off the mark; off base; misdirected; irrelevant
Describes a remark, action, or idea that misses the intended point or is not pertinent to the matter at hand. Often used in criticism or self-deprecation.
His opinion was off the mark.
的外れな質問をしてしまった。
I ended up asking an irrelevant question.