noun
eldest sister
Rare term for one's eldest sister. In modern Japanese, 長女 (eldest daughter) or 一番上の姉 (oldest sister) are far more common.
古文書では「大姉」を「おおあね」と読ませて長姉を指すことがある。
In old documents, 大姉 is sometimes read as おおあね and refers to the eldest sister.