early 15c., from Old French dominion "dominion, rule, power," from Medieval Latin dominionem (nominative dominio), corresponding to Latin dominium "property, ownership," from dominus (see domination).British sovereign colonies often were called dominions, hence the Dominion of Canada, the formal title after the 1867 union, and Old Dominion, the popular name for the U.S. state of Virginia, first recorded 1778.