fun vs incentive

fun

adj
  • Whimsical or flamboyant. 

  • Enjoyable or amusing. 

noun
  • playful, often noisy, activity. 

  • amusement, enjoyment or pleasure 

verb
  • To tease, kid, poke fun at, make fun of. 

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 fun and incentive occurred in a corpus of books? (source: Google Ngram Viewer )