exponential decay vs decay

exponential decay and decay both are nouns.

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

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

Other hypernyms of exponential decay include decline.

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