author vs writing

author and writing both are nouns.

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

author (noun)	writing (noun)
writes (books or stories or articles or the like) professionally (for pay)	the activity of putting something in written form
someone who originates or causes or initiates something	the act of creating written works
	the work of a writer; anything expressed in letters of the alphabet (especially when considered from the point of view of style and effect)
	letters or symbols that are written or imprinted on a surface to represent the sounds or words of a language
	(usually plural) the collected work of an author

author (verb)	writing (verb)
be the author of