regime vs authorities

regime and authorities both are nouns.

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

As nouns, regime and authorities are synonyms defined as:

regime and authorities: the organization that is the governing authority of a political unit

Other synonyms of regime include government.

regime (noun)	authorities (noun)
(medicine) a systematic plan for therapy (often including diet)	the organization that is the governing authority of a political unit
the organization that is the governing authority of a political unit