national leader vs Alexander Kerensky

national leader and Alexander Kerensky both are nouns.

Word	Noun	Adjective	Verb	Adverb
national leader	Yes	No	No	No
Alexander Kerensky	Yes	No	No	No

national leader (noun)	Alexander Kerensky (noun)
a person who is a respected leader in national or international affairs	Russian revolutionary who was head of state after Nicholas II abdicated but was overthrown by the Bolsheviks (1881-1970)