back out vs retreat

back out

verb
  • To undo (a change). 

  • To withdraw from something one has agreed to do. 

  • To exit a mode or function. 

  • To draw from behind the back [+accusative = a knife etc.] (as also bare back). 

  • Coordinate terms: cancel, call off, get cold feet 

  • To reverse (a vehicle) from a confined space. 

  • See also: sell short 

  • To dare (someone) to not withdraw from a challenge. 

  • To bet on someone losing. 

  • Coordinate term: scare off 

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 back out and retreat occurred in a corpus of books? (source: Google Ngram Viewer )