despondency vs regret

despondency

noun
  • A feeling of depression or disheartenment. 

  • The loss of hope or confidence; despair or dejection. 

regret

noun
  • Emotional pain on account of something done or experienced in the past, with a wish that it had been different; a looking back with dissatisfaction or with longing. 

  • The amount of avoidable loss that results from choosing the wrong action. 

verb
  • To feel sorry about (a thing that has or has not happened), afterthink: to wish that a thing had not happened, that something else had happened instead. 

  • To feel sorry about (any thing). 

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