hierarch vs prelate

hierarch and prelate both are nouns.

Word	Noun	Adjective	Verb	Adverb
hierarch	Yes	No	No	No
prelate	Yes	No	No	No

As nouns, hierarch and prelate are synonyms defined as:

Other synonyms of hierarch include archpriest, high priest, primate.

hierarch (noun)	prelate (noun)
a senior clergyman and dignitary	a senior clergyman and dignitary
a person who holds a high position in a hierarchy