enduringly vs weakly

enduringly

adv
  • In an enduring manner or fashion; so as to endure or last. 

weakly

adj
  • Frail, sickly or of a delicate constitution; weak. 

adv
  • With little strength or force. 

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