A woman who takes the place of the mother in suckling and bringing up a child; a nurse.(noun)
The Century Dictionary (Public Domain)
Use "foster-mother" in a sentence
"But Rome is my foster-mother, and were I untrue to her, of little pride, of little worth would be my love for you."
"But even beyond that, it was more the people that I met later on in life that were such a great influence on me, like y foster-mother, Betsey Shirley."
"They were spiritual orphans then, not yet embracing, as foster-mother, the Catholic church."