downfall vs gangrene

downfall

verb
  • To fall down; deteriorate; decline. 

noun
  • The cause of such a fall; a critical blow or error. 

  • A precipitous decline in fortune; death or rapid deterioration, as in status or wealth. 

  • An act of falling down. 

gangrene

verb
  • To corrupt; To cause to become degenerate. 

  • To produce gangrene in. 

  • To be affected with gangrene. 

noun
  • The necrosis or rotting of flesh, usually caused by lack of blood supply. 

  • A damaging or corrupting influence. 

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