compelling vs somnific

compelling

adj
  • Strongly or irresistibly evoking interest or attention. 

  • Forceful. 

noun
  • An act of compulsion; an obliging somebody to do something. 

somnific

adj
  • Causing sleep; somniferous. 

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