decadency vs degradation

decadency and degradation both are nouns.

Word	Noun	Adjective	Verb	Adverb
decadency	Yes	No	No	No
degradation	Yes	No	No	No

As nouns, degradation is a hypernym of decadency; that is, degradation is a word with a broader meaning than decadency:

Other hypernyms of decadency include abasement, abjection.

decadency (noun)	degradation (noun)
the state of being degenerate in mental or moral qualities	changing to a lower state (a less respected state)
	a low or downcast state