imperium vs authorization

imperium and authorization both are nouns.

Word	Noun	Adjective	Verb	Adverb
imperium	Yes	No	No	No
authorization	Yes	No	No	No

As nouns, authorization is a hypernym of imperium; that is, authorization is a word with a broader meaning than imperium:

Other hypernyms of imperium include authorisation, authority, dominance, potency, say-so.

imperium (noun)	authorization (noun)
supreme authority; absolute dominion	the act of conferring legality or sanction or formal warrant
the domain ruled by an emperor or empress; the region over which imperial dominion is exercised	the power or right to give orders or make decisions
	official permission or approval
	a document giving an official instruction or command