postulator vs Church of Rome

postulator and Church of Rome both are nouns.

Word	Noun	Adjective	Verb	Adverb
postulator	Yes	No	No	No
Church of Rome	Yes	No	No	No

postulator (noun)	Church of Rome (noun)
someone who assumes or takes something for granted as the basis of an argument	the Christian Church based in the Vatican and presided over by a pope and an episcopal hierarchy
(Roman Catholic Church) someone who proposes or pleads for a candidate for beatification or canonization