boon vs kiss of death

boon

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. 

adj
  • gay; merry; jovial; convivial. 

kiss of death

noun
  • A kiss on the cheek that signifies the death of the receiver, as delivered by a mob boss or one with such influence. 

  • Something that may seem good and favourable but that actually brings ruin to hopes, plans, etc. 

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