author vs coiner

author and coiner both are nouns.

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

As nouns, coiner is a hyponym of author; that is, coiner is a word with a more specific, narrower meaning than author:

author (noun)	coiner (noun)
writes (books or stories or articles or the like) professionally (for pay)	a skilled worker who coins or stamps money
someone who originates or causes or initiates something	someone who is a source of new words or new expressions
	a maker of counterfeit coins

author (verb)	coiner (verb)
be the author of