boon vs exceptional

boon

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

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

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

adj
  • gay; merry; jovial; convivial. 

exceptional

noun
  • An exception, or something having an exceptional value 

adj
  • Corresponding to something of lower dimension under a birational correspondence. 

  • Forming an exception; not ordinary; uncommon; rare. 

  • Better than the average; superior due to exception or rarity. 

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