Farrell vs author

Farrell and author both are nouns.

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

Farrell (noun)	author (noun)
United States operatic soprano noted for the clarity and power of her voice (1920-2002)	writes (books or stories or articles or the like) professionally (for pay)
United States writer remembered for his novels (1904-1979)	someone who originates or causes or initiates something

Farrell (verb)	author (verb)
	be the author of