Meaning

noun the domain ruled by an emperor or empress; the region over which imperial dominion is exercised

noun a group of countries under a single authority

noun a monarchy with an emperor as head of state

originFrom Middle English empire, from Old French empire, empere, from Latin imperium, inperium (“command, control, dominion, sovereignty, a dominion, empire”), from imperare, inperare (“to command, order”), from in (“in, on”) + parare (“to make ready, order”). Doublet of empery and imperium.

Etymology from Wiktionary, CC BY-SA 3.0