What is the meaning of Empire?

noun

• The domain ruled by an emperor or empress; the region over which imperial dominion is exercised.
  • synonyms: imperium
• A group of countries under a single authority.
  • usage: "the British created a great empire"
• A monarchy with an emperor as head of state.
• A group of diverse companies under common ownership and run as a single organization.
  • synonyms: conglomerate
• An eating apple that somewhat resembles a McIntosh; used as both an eating and a cooking apple. .