reverse split vs diminution

reverse split and diminution both are nouns.

Word	Noun	Adjective	Verb	Adverb
reverse split	Yes	No	No	No
diminution	Yes	No	No	No

As nouns, diminution is a hypernym of reverse split; that is, diminution is a word with a broader meaning than reverse split:

reverse split: a decrease in the number of outstanding shares of a corporation without changing the shareholders' equity
diminution: the act of decreasing or reducing something

Other hypernyms of reverse split include decrease, reduction, step-down.

reverse split (noun)	diminution (noun)
a decrease in the number of outstanding shares of a corporation without changing the shareholders' equity	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