engorgement vs flash flood

engorgement

noun
  • The process or the condition of becoming engorged, becoming over-filled with fluid. 

  • The act of swallowing greedily. 

flash flood

noun
  • A sudden, rapid flood, usually of short duration and local impact. 

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