empire

noun

1.
the domain ruled by an emperor or empress; the region over which imperial dominion is exercised
imperium
Derived from:
imperial
2.
a group of countries under a single authority
coserrich onewield thedeness WF keizerry
3.
a monarchy with an emperor as head of state
Derived from:
imperial
4.
a group of diverse companies under common ownership and run as a single organization
conglomerate