overburden vs overwhelm

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. 

overwhelm

verb
  • To overpower, crush. 

  • To overpower emotionally. 

  • To cause to surround, to cover. 

  • To engulf, surge over and submerge. 

noun
  • The state or condition of being overwhelmed. 

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