overburden vs refresh

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. 

refresh

noun
  • The periodic energizing required to maintain the contents of computer memory, the display luminance of a computer screen, etc. 

  • The update of a display (in a web browser or similar software) to show the latest version of the data. 

  • The process of modernizing something. 

verb
  • To perform the periodic energizing required to maintain the contents of computer memory, the display luminance of a computer screen, etc. 

  • To become fresh again; to be revitalized. 

  • To renew or revitalize. 

  • To cause (a web browser or similar software) to refresh its display. 

  • To reload (a document, especially a webpage) and show any new changes. 

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