back out vs deliver

back out

verb
  • 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). 

  • To undo (a change). 

  • 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 

deliver

verb
  • To hand over or surrender (someone or something) to another. 

  • To give birth to. 

  • To set free from restraint or danger. 

  • To free from or disburden of anything. 

  • To bring or transport something to its destination. 

  • To produce what is expected or required. 

  • To express in words or vocalizations, declare, utter, or vocalize. 

  • To discover; to show. 

  • To administer a drug. 

  • To assist in the birth of. 

  • To give forth in action or exercise; to discharge. 

  • To assist (a female) in bearing, that is, in bringing forth (a child). 

adj
  • Capable, agile, or active. 

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