papacy vs regime

papacy and regime both are nouns.

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

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

papacy: the government of the Roman Catholic Church
regime: the organization that is the governing authority of a political unit

Other hypernyms of papacy include authorities, government.

papacy (noun)	regime (noun)
the government of the Roman Catholic Church	(medicine) a systematic plan for therapy (often including diet)
	the organization that is the governing authority of a political unit