avidity vs pessimism

avidity

noun
  • Greediness; strong appetite. 

  • The measure of the synergism of the strength of individual interactions between proteins. 

  • Eagerness; intenseness of desire. 

pessimism

noun
  • A general belief that bad things will happen. 

  • The condition of being pessimal. 

  • The doctrine that this world is the worst of all possible worlds. 

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