muddle vs overburden

muddle

verb
  • To waste or misuse, as one does who is stupid or intoxicated. 

  • To dabble in mud. 

  • To mash slightly for use in a cocktail. 

  • To think and act in a confused, aimless way. 

  • To cloud or stupefy; to render stupid with liquor; to intoxicate partially. 

  • To mix together, to mix up; to confuse. 

  • To make turbid or muddy. 

noun
  • A mixture of crushed ingredients, as prepared with a muddler. 

  • A mixture; a confusion; a garble. 

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 muddle and overburden occurred in a corpus of books? (source: Google Ngram Viewer )