depart vs retreat

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. 

retreat

verb
  • To withdraw from a position, go back. 

  • To slope back. 

  • To withdraw military forces 

  • To shrink back due to generally warmer temperatures. 

  • a retreating forehead 

noun
  • A peaceful, quiet place affording privacy or security. 

  • The act of reversing direction and receding from a forward position. 

  • A bugle call or drumbeat signaling the lowering of the flag at sunset, as on a military base. 

  • A military ceremony to lower the flag. 

  • The move of a piece from a threatened position. 

  • A period of retirement, seclusion, or solitude. 

  • A period of meditation, prayer or study. 

  • The act of pulling back or withdrawing, as from something dangerous, or unpleasant. 

  • A signal for a military withdrawal. 

  • Withdrawal by military force from a dangerous position or from enemy attack. 

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