engender vs fall off

engender

verb
  • To assume form; to come into existence; to be caused or produced. 

  • To give existence to, to produce (living creatures). 

  • To bring into existence (a situation, quality, result etc.); to give rise to, cause, create. 

  • To endow with gender; to create gender or enhance the importance of gender. 

fall off

verb
  • To become detached or to drop from. 

  • To diminish in size, value, etc. 

  • To fall into sin; stray. 

  • To change the direction of the sail so as to point in a direction that is more down wind; to bring the bow leeward. 

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