approbation vs coolness

approbation

noun
  • The act of approving; an assenting to the propriety of a thing with some degree of pleasure or satisfaction; approval, sanction, commendation or official recognition. 

coolness

noun
  • Indifference; lack of passion or interest. 

  • The state of being cool, i.e. calm. 

  • The state of being cool, i.e. good or pleasing. 

  • The result or product of being cool, i.e. good or pleasing. 

  • The state of being cool, i.e. chilly. 

  • The result or product of being cool, i.e. chilly. 

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