incentive vs projectile

incentive

adj
  • Inciting; encouraging or moving; rousing to action; stimulating. 

  • Serving to kindle or set on fire. 

noun
  • Something that motivates, rouses, or encourages. 

  • A bonus or reward, often monetary, to work harder. 

projectile

adj
  • Caused or imparted by impulse or projection; impelled forward. 

  • Projecting or impelling forward. 

noun
  • an object intended to be or having been fired from a weapon. 

  • any object propelled through space by the application of a force. 

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