awaken vs nod off

awaken

verb
  • To cause to become aware. 

  • To call to a sense of sin. 

  • To cause to become awake. 

  • To bring into action (something previously dormant); to stimulate. 

  • To stop sleeping; awake. 

nod off

verb
  • To fall asleep, especially unintentionally. 

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