composition vs author

composition and author both are nouns.

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

composition (noun)	author (noun)
the act of creating written works	writes (books or stories or articles or the like) professionally (for pay)
musical creation	someone who originates or causes or initiates something
something that is created by arranging several things to form a unified whole
the way in which someone or something is composed
the spatial property resulting from the arrangement of parts in relation to each other and to the whole
an essay (especially one written as an assignment)
a musical work that has been created
art and technique of printing with movable type
a mixture of ingredients

composition (verb)	author (verb)
	be the author of