A wrong guess or estimate; off the mark—an opinion or prediction that misses the point.
君の推理は残念ながら見当外れだった。
Unfortunately, your deduction was off the mark.
その答えは見当外れで、問題の意図を理解していないようだ。
That answer is misguided; it seems you didn't understand the point of the question.
見当外れな指摘をされて気まずくなった。
I felt awkward after receiving an off-target remark.