depart vs turn back

depart

verb
  • To go away from; to leave. 

  • To leave. 

  • To die. 

  • To disappear, vanish; to cease to exist. 

  • To deviate (from), be different (from), fail to conform. 

  • To set out on a journey. 

turn back

verb
  • To return to a previous state of being. 

  • To cause to reverse direction and retrace one's steps. 

  • To reverse direction and retrace one's steps. 

  • To prevent or refuse to allow passage or progress. 

  • To adjust to a previous setting. 

  • To fold something back; to fold down. 

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