mistaking for; failing to recognize
Refers to the act of misidentifying someone or something, or failing to recognize them correctly. Often used in contexts where one person or thing is mistaken for another.
I mistook someone for someone else and ended up speaking to a stranger.
It was dark, and I failed to recognize his face.
Compound of 見 (mi, 'seeing') + 違い (chigai, 'difference, mistake'). The exact historical derivation is uncertain, but it follows a common pattern for nouns describing mistaken perception.