noun
sailor suit; middy uniform
Refers to the classic sailor-style outfit, originally naval-inspired, now iconic as a Japanese school uniform for girls.
彼女はセーラー服を着て学校に行った。
She went to school wearing a sailor suit.
noun
sailor-style school uniform; two-piece school uniform
Specifically the two-piece school uniform with a sailor collar, commonly worn by Japanese middle and high school girls.
この学校のセーラー服は紺色だ。
This school's sailor uniform is navy blue.