discourage vs overburden

discourage

noun
  • Lack of courage 

verb
  • To extinguish the courage of; to dishearten; to depress the spirits of; to deprive of confidence; to deject. 

  • To persuade somebody not to do (something). 

overburden

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. 

verb
  • To overload or overtax. 

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