narcotic vs sleeping pill

narcotic

noun
  • Any type of numbing or soothing drug. 

  • Any substance or drug that reduces pain, induces sleep and may alter mood or behaviour; in some contexts, especially in reference to the opiates-and-opioids class, especially in reference to illegal drugs, and often both. 

adj
  • Of, or relating to narcotics. 

  • Inducing sleep; causing narcosis. 

sleeping pill

noun
  • A pill or tablet having a soporific effect. 

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