mourning vs regret

mourning

noun
  • Feeling or expressing sorrow over someone's death. 

  • The traditional clothes worn by those who mourn (in Western societies, typically coloured black). 

  • The act of expressing or feeling sorrow or regret; lamentation. 

  • Drapes or coverings associated with mourning. 

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 mourning and regret occurred in a corpus of books? (source: Google Ngram Viewer )