spoil vs upgrade

spoil

verb
  • To ruin; to damage (something) in some way making it unfit for use. 

  • To ruin the character of, by overindulgence; to coddle or pamper to excess. 

  • To reveal the ending or major events of (a story etc.); to ruin (a surprise) by exposing it ahead of time. 

  • To render (a ballot paper) invalid by deliberately defacing it. 

  • Of food, to become bad, sour or rancid; to decay. 

  • To reduce the lift generated by an airplane or wing by deflecting air upwards, usually with a spoiler. 

noun
  • Material (such as rock or earth) removed in the course of an excavation, or in mining or dredging. Tailings. Such material could be utilised somewhere else. 

  • Plunder taken from an enemy or victim. 

upgrade

verb
  • To replace with something better. 

  • To improve, usually applied to technology, generally by complete replacement of one or more components 

  • To improve the equipment or furnishings of or services rendered to 

  • To replace a program with a later version of itself, a version having a higher version number or marketed under a more recent product name. 

  • To improve in condition or status. 

noun
  • An upward grade or slope. 

  • An improvement 

  • An improved component or replacement item, usually applied to technology 

adv
  • Up a slope or grade. 

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