noun
stand-up collar; mandarin collar
Refers to a collar that stands up around the neck, such as on a mandarin-collar shirt or a military-style jacket.
彼は立ち襟のシャツを着ている。
He is wearing a shirt with a stand-up collar.
Compound of 立ち (tachi, 'standing') + 襟 (eri, 'collar').