noun
younger female cousin
Specifically a female cousin who is younger than the speaker. Compare 従姉 (older female cousin), 従弟 (younger male cousin), and 従兄 (older male cousin).
See also: 従姉
私の従妹は来年高校を卒業する。
My younger female cousin will graduate from high school next year.
夏休みに従妹が遊びに来た。
My younger female cousin came to visit during summer vacation.