一目惚れ means “fall in love at first glance/sight”, where 一目 means “one glance/eye” and 惚れ comes from the verb 惚(ほ)れる, meaning “be romantically attracted/fall in love”. You can also use this word to describe the situation when you really like something (e.g. clothes) upon first glance
This morning, I fell in love with this girl I don’t know at the station.
I got attached to these clothes at first sight and bought them immediately.