literary hack vs author

literary hack and author both are nouns.

Word	Noun	Adjective	Verb	Adverb
literary hack	Yes	No	No	No
author	Yes	No	Yes	No

As nouns, author is a hypernym of literary hack; that is, author is a word with a broader meaning than literary hack:

literary hack: a mediocre and disdained writer
author: writes (books or stories or articles or the like) professionally (for pay)

Other hypernyms of literary hack include writer.

literary hack (noun)	author (noun)
a mediocre and disdained writer	writes (books or stories or articles or the like) professionally (for pay)
	someone who originates or causes or initiates something

literary hack (verb)	author (verb)
	be the author of