·noun Dominion; empire; authority.
II. Domain ·noun Landed property; estate; especially, the land about the mansion house of a lord, and in his immediate occupancy; demesne.
III. Domain ·noun Ownership of land; an estate or patrimony which one has in his own right; absolute proprietorship; paramount or sovereign ownership.
IV. Domain ·noun The territory over which dominion or authority is exerted; the possessions of a sovereign or commonwealth, or the like. Also used figuratively.