convalesce vs take heart

convalesce

verb
  • To recover health and strength gradually after sickness or weakness. 

take heart

verb
  • To be courageous; to regain one's courage. 

intj
  • Used when encouraging someone to bear or take up a difficult situation. 

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