Source : Webster's Revised Unabridged Dictionary (1913)

Adynamia \Ad`y*na"mi*a\, n. [NL. adynamia, fr. Gr. ? want of
   strength; ? priv + ? power, strength.] (Med.)
   Considerable debility of the vital powers, as in typhoid
   fever. --Dunglison.

Source : WordNet®

adynamia
     n : lack of strength or vigor (especially from illness)