plaint vs sorrow

plaint

noun
  • A complaint. 

  • An accusation. 

sorrow

noun
  • (usually in plural) An instance or cause of unhappiness. 

  • unhappiness, woe 

verb
  • To feel grief over; to mourn, regret. 

  • To feel or express grief. 

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