encouragement vs tranquilizer

encouragement

noun
  • Words or actions that increase someone's confidence 

  • Something that incites, supports, promotes, protects or advances; incentive 

  • The feeling of being encouraged 

  • The act of encouraging 

tranquilizer

noun
  • That which tranquillizes or soothes. 

  • A drug used to reduce anxiety or tension. 

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