debility vs feebleness

debility and feebleness both are nouns.

Word	Noun	Adjective	Verb	Adverb
debility	Yes	No	No	No
feebleness	Yes	No	No	No

As nouns, debility and feebleness are synonyms defined as:

debility and feebleness: the state of being weak in health or body (especially from old age)

Other synonyms of debility include frailness, frailty, infirmity, valetudinarianism.

debility (noun)	feebleness (noun)
the state of being weak in health or body (especially from old age)	the quality of lacking intensity or substance
	the state of being weak in health or body (especially from old age)