部屋へや住ずみ

noun

adult son living at home without inheritance; dependent adult child

Historically referred to an eldest son who had not yet inherited the family estate and remained dependent on his parents. In modern usage, it can describe any adult child still living at home and financially dependent, often with a slightly negative or pitiful connotation.

• 江え戸ど時じ代だい、部屋へや住ずみの長ちょう男なんは父ちち親おやが隠いん居きょするまで家か督とくを継つげなかった。

  In the Edo period, the eldest son who was a heyazumi could not inherit the family headship until his father retired.

• 彼かれは三さん十じゅっ歳さいを過すぎても部屋へや住ずみで、親おやのすねをかじっている。

  He is over thirty and still a heyazumi, living off his parents.