noun
foster parent; parent substitute; acting as a parent
Refers to a person or role that takes the place of a parent, often in a caregiving or guardianship context. Can be used for relatives, guardians, or even institutions acting in loco parentis.
彼は姉の子供たちの親代わりになった。
He became a parent substitute for his sister's children.
親代わりとし
As a foster parent, she raised the child.