empire vs authorities

empire and authorities both are nouns.

Word	Noun	Adjective	Verb	Adverb
empire	Yes	No	No	No
authorities	Yes	No	No	No

As nouns, authorities is a hypernym of empire; that is, authorities is a word with a broader meaning than empire:

empire: a group of countries under a single authority
authorities: the organization that is the governing authority of a political unit

Other hypernyms of empire include government, regime.

empire (noun)	authorities (noun)
a monarchy with an emperor as head of state	the organization that is the governing authority of a political unit
a group of countries under a single authority
a group of diverse companies under common ownership and run as a single organization
the domain ruled by an emperor or empress; the region over which imperial dominion is exercised