forcible vs incentive

forcible

adj
  • Having a powerful effect; forceful, telling, strong, convincing, effective. 

  • Able to be forced. 

  • Done by force, forced. 

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. 

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