patron saint vs Saint Crispin

patron saint and Saint Crispin both are nouns.

Word	Noun	Adjective	Verb	Adverb
patron saint	Yes	No	No	No
Saint Crispin	Yes	No	No	No

patron saint (noun)	Saint Crispin (noun)
a saint who is considered to be a defender of some group or nation	patron saint of shoemakers; he and his brother were martyred for trying to spread Christianity (3rd century)