Concubine

Chamber's Twientieth Century Dictionary · 1908 · p. 23

kong′kū-bīn, n. a woman who cohabits or lives with a man without being married.— n. Concū′binage , state of living together as man and wife without being married.— adj. Concū′binary . [Fr.,—L. concubina — con , together, cubāre , to lie down.]