matrimony (n.)

c. 1300, matrimoine, "the married state, the relation of husband and wife, wedlock; the sacrament of marriage," from Old French matremoine "matrimony, marriage" and directly from Latin mātrimōnium "wedlock, marriage" (in plural "wives"), from mātrem (nominative māter) "mother" (see mother (n.1)) + -mōnium, suffix signifying "action, state, condition."