physicist vs Sir Joseph John Thomson

physicist and Sir Joseph John Thomson both are nouns.

Word	Noun	Adjective	Verb	Adverb
physicist	Yes	No	No	No
Sir Joseph John Thomson	Yes	No	No	No

physicist (noun)	Sir Joseph John Thomson (noun)
a scientist trained in physics	English physicist who experimented with the conduction of electricity through gases and who discovered the electron and determined its charge and mass (1856-1940)