overburden vs overcome

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. 

overcome

verb
  • To come or pass over; to spread over. 

  • To surmount (a physical or abstract obstacle); to prevail over, to get the better of. 

  • To prevail. 

  • To win or prevail in some sort of battle, contest, etc. 

  • To recover from (a difficulty), to get over 

noun
  • The burden or recurring theme in a song. 

  • A surplus. 

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