boon vs cruelty

boon

adj
  • gay; merry; jovial; convivial. 

noun
  • The woody portion of flax, separated from the fiber as refuse matter by retting, braking, and scutching. 

  • A good thing; a blessing or benefit; a thing to be thankful for. 

  • An unpaid service due by a tenant to his lord. 

cruelty

noun
  • An indifference to suffering or pleasure in inflicting suffering. 

  • A cruel act. 

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