Originally: severe physical weakness; prostration; debility.
((n.) Considerable debility of the vital powers, as in typhoid
fever.)
Origin:
Mid 18th century; earliest use found in Robert James (d. 1776), physician and inventor of James's fever powder. From post-classical Latin adynamia from ancient Greek ἀδυναμία lack of strength, weakness, debility from ἀ + δύναμις power + -ία.