'Concubines' in the Bible

David took more concubines and wives from Jerusalem after he came from Hebron, and more sons and daughters [were] born to him.

The king went out with all his household {following him}, but the king left behind ten concubines to look after the house.

And Ahithophel said to Absalom, "Go to the concubines of your father whom he left behind to watch over the house, then all of Israel will hear that you made yourself odious to your father, and {all of your followers will be motivated}!"

Then they pitched a tent for Absalom on the roof, and he went [in] to the concubines of his father before the eyes of all Israel.

Then Joab came to the king's house and said, "Today you have humiliated the faces of all of your servants who have saved your life this day, and the life of your sons and your daughters, the life of your wives, and the life of your concubines,

David went up to his house in Jerusalem, then the king took the ten concubines whom he had left to look after the house, and he put them {under confinement}. However, he provided for them, but {he did not sleep with them}. So they were confined until the day of their death, like a lifetime of widowhood.