exponential return vs decay

exponential return and decay both are nouns.

Word	Noun	Adjective	Verb	Adverb
exponential return	Yes	No	No	No
decay	Yes	No	Yes	No

As nouns, decay is a hypernym of exponential return; that is, decay is a word with a broader meaning than exponential return:

Other hypernyms of exponential return include decline.

exponential return (noun)	decay (noun)
a decrease that follows an exponential function	the organic phenomenon of rotting
	a gradual decrease; as of stored charge or current
	the process of gradually becoming inferior
	the spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation
	an inferior state resulting from the process of decaying

exponential return (verb)	decay (verb)
	fall into decay or ruin
	lose a stored charge, magnetic flux, or current
	undergo decay or decomposition