Parker vs author

Parker and author both are nouns.

Word	Noun	Adjective	Verb	Adverb
Parker	Yes	No	No	No
author	Yes	No	Yes	No

Parker (noun)	author (noun)
United States writer noted for her sharp wit (1893-1967)	writes (books or stories or articles or the like) professionally (for pay)
United States saxophonist and leader of the bop style of jazz (1920-1955)	someone who originates or causes or initiates something

Parker (verb)	author (verb)
	be the author of