infirmity vs feebleness

infirmity and feebleness both are nouns.

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

As nouns, infirmity and feebleness are synonyms defined as:

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

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

infirmity (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)