celebrant vs priest

celebrant and priest both are nouns.

Word	Noun	Adjective	Verb	Adverb
celebrant	Yes	No	No	No
priest	Yes	No	No	No

As nouns, priest is a hypernym of celebrant; that is, priest is a word with a broader meaning than celebrant:

celebrant: an officiating priest celebrating the Eucharist
priest: a clergyman in Christian churches who has the authority to perform or administer various religious rites; one of the Holy Orders

celebrant (noun)	priest (noun)
an officiating priest celebrating the Eucharist	a clergyman in Christian churches who has the authority to perform or administer various religious rites; one of the Holy Orders
a person who is celebrating	a person who performs religious duties and ceremonies in a non-Christian religion