'Servant girl' in the Bible

Now Abram's wife Sarai had not borne a child for him. She had an Egyptian servant girl whose name was Hagar.

And Laban gave Zilpah, his servant-girl, to Leah, to be her waiting-woman.

And Laban gave Rachel his servant-girl Bilhah to be her waiting-woman.

Then she said, "Here [is] my servant girl Bilhah; go in to her that she may bear children {as my surrogate}. Then I will even {have children} by her."

Then Leah said, "God has given [me] my wage since I gave my servant girl to my husband." And she called his name Issachar.