flamen vs priest

flamen and priest both are nouns.

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

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

flamen: a priest who served a particular deity in ancient Rome
priest: a person who performs religious duties and ceremonies in a non-Christian religion

Other hypernyms of flamen include non-Christian priest.

flamen (noun)	priest (noun)
a priest who served a particular deity in ancient Rome	a clergyman in Christian churches who has the authority to perform or administer various religious rites; one of the Holy Orders
	a person who performs religious duties and ceremonies in a non-Christian religion