anxiolytic vs tranquilizer

anxiolytic

noun
  • A drug prescribed for the treatment of symptoms of anxiety. 

adj
  • That reduces anxiety; tranquilizing 

tranquilizer

noun
  • A drug used to reduce anxiety or tension. 

  • That which tranquillizes or soothes. 

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