deluge vs overburden

deluge

verb
  • To overwhelm. 

  • To flood with water. 

noun
  • A great flood or rain. 

  • An overwhelming amount of something; anything that overwhelms or causes great destruction. 

  • A system for flooding or drenching a space, container, or area with water in an emergency to prevent or extinguish a fire. 

overburden

verb
  • To overload or overtax. 

noun
  • A sterile stratum that lies above the stratum being investigated 

  • The rock and subsoil that lies above a mineral deposit such as a coal seam. 

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