navy-blue knee socks
Slang abbreviation of 紺色のハイソックス (navy-blue knee-high socks). Used in casual contexts, especially among young people.
That girl looks really good in navy-blue knee socks.
Navy-blue knee socks are specified as part of the uniform.
Abbreviation of 紺色のハイソックス (navy-blue knee-high socks), where ハイソ is a clipping of ハイソックス.