old master vs Michelangelo Merisi da Caravaggio

old master and Michelangelo Merisi da Caravaggio both are nouns.

Word	Noun	Adjective	Verb	Adverb
old master	Yes	No	No	No
Michelangelo Merisi da Caravaggio	Yes	No	No	No

old master (noun)	Michelangelo Merisi da Caravaggio (noun)
a great European painter prior to 19th century	Italian painter noted for his realistic depiction of religious subjects and his novel use of light (1571-1610)