authoritarian regime vs regime

authoritarian regime and regime both are nouns.

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

As nouns, regime is a hypernym of authoritarian regime; that is, regime is a word with a broader meaning than authoritarian regime:

authoritarian regime: a government that concentrates political power in an authority not responsible to the people
regime: the organization that is the governing authority of a political unit

Other hypernyms of authoritarian regime include authorities, government.

authoritarian regime (noun)	regime (noun)
a government that concentrates political power in an authority not responsible to the people	(medicine) a systematic plan for therapy (often including diet)
	the organization that is the governing authority of a political unit