incentive vs kissing cousin

incentive

noun
  • Something that motivates, rouses, or encourages. 

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

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

  • Serving to kindle or set on fire. 

kissing cousin

noun
  • A thing which is related or similar to another thing. 

  • A relatively distant relative, or a friend, who is familiar enough to be greeted with a kiss. 

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