menage (n.)

1690s, "management of a household, domestic establishment," from French ménage, from Old French manage "household, family dwelling" (12c.), from Vulgar Latin *mansionaticum "household, that which pertains to a house," from Latin mansionem "dwelling" (see mansion).

Now generally used in suggestive borrowed French phrase ménage à trois (by 1853 in English publications; by 1841 in French as the title of an opéra comique) "a domestic arrangement or relationship consisting of a husband, a wife, and the lover of one or the other," literally "household of three." The word had been in Middle English as mayngnage, maynage (c. 1300) in the senses "a household, a domestic establishment, company of persons living together in a house," but this was obsolete by c. 1500.