papal bull vs edict

papal bull and edict both are nouns.

Word	Noun	Adjective	Verb	Adverb
papal bull	Yes	No	No	No
edict	Yes	No	No	No

As nouns, edict is a hypernym of papal bull; that is, edict is a word with a broader meaning than papal bull:

papal bull: a formal proclamation issued by the pope (usually written in antiquated characters and sealed with a leaden bulla)
edict: a legally binding command or decision entered on the court record (as if issued by a court or judge)

Other hypernyms of papal bull include decree, fiat, order, rescript.

papal bull (noun)	edict (noun)
a formal proclamation issued by the pope (usually written in antiquated characters and sealed with a leaden bulla)	a legally binding command or decision entered on the court record (as if issued by a court or judge)
	a formal or authoritative proclamation