laxative vs tranquilizer

laxative

noun
  • Any substance, such as a food or in the form of a medicine which has a laxative effect. 

adj
  • Having the effect of moving the bowels, or aiding digestion and preventing constipation. 

tranquilizer

noun
  • A drug used to reduce anxiety or tension. 

  • That which tranquillizes or soothes. 

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