astheny vs infirmity

astheny and infirmity both are nouns.

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

As nouns, infirmity is a hypernym of astheny; that is, infirmity is a word with a broader meaning than astheny:

astheny: an abnormal loss of strength
infirmity: the state of being weak in health or body (especially from old age)

Other hypernyms of astheny include debility, feebleness, frailness, frailty, valetudinarianism.

astheny (noun)	infirmity (noun)
an abnormal loss of strength	the state of being weak in health or body (especially from old age)