乳ち姉妹きょうだい

noun

foster sister

Refers to a girl who is not related by blood but was nursed by the same woman, making her a foster sister. The term is relatively rare and may be encountered in historical or literary contexts.

See also: 乳兄弟 (ちきょうだい)

• 彼かの女じょは私わたしの乳ち姉妹きょうだいで、同おなじ乳母うばに育そだてられた。

  She is my foster sister, raised by the same wet nurse.