diminish vs diminution

diminish is not a noun while diminution is a noun.

Word	Noun	Adjective	Verb	Adverb
diminish	No	No	Yes	No
diminution	Yes	No	No	No

diminish (noun)	diminution (noun)
	the act of decreasing or reducing something
	the statement of a theme in notes of lesser duration (usually half the length of the original)
	change toward something smaller or lower

diminish (verb)	diminution (verb)
decrease in size, extent, or range
lessen the authority, dignity, or reputation of