asthenic vs impuissant

asthenic

adj
  • Characterized by, or pertaining to, debility; weak; debilitating. 

noun
  • A person who has asthenia. 

impuissant

adj
  • weak; impotent; feeble 

How often have the words asthenic and impuissant occurred in a corpus of books? (source: Google Ngram Viewer )