adequate vs exceptional

adequate

adj
  • Equal to or fulfilling some requirement. 

det
  • A sufficient amount of; enough. 

exceptional

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

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

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

noun
  • An exception, or something having an exceptional value 

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