national leader vs Cosimo de Medici

national leader and Cosimo de Medici both are nouns.

Word	Noun	Adjective	Verb	Adverb
national leader	Yes	No	No	No
Cosimo de Medici	Yes	No	No	No

national leader (noun)	Cosimo de Medici (noun)
a person who is a respected leader in national or international affairs	Italian financier and statesman and friend of the papal court (1389-1464)