What is "adynamia"

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

n. Lack or loss of strength, usually due to a disease.

n. lack of strength or vigor (especially from illness)

Adynamia means lack of strength or vigor due to a pathological condition. It is often associated with a range of neurological diseases such as multiple sclerosis and medial- frontal lobe lesions.