high priest vs John Henry Newman

high priest and John Henry Newman both are nouns.

Word	Noun	Adjective	Verb	Adverb
high priest	Yes	No	No	No
John Henry Newman	Yes	No	No	No

high priest (noun)	John Henry Newman (noun)
a senior clergyman and dignitary	English prelate and theologian who (with John Keble and Edward Pusey) founded the Oxford movement; Newman later turned to Roman Catholicism and became a cardinal (1801-1890)
a preeminent authority or major proponent of a movement or doctrine