mistake vs mullock

mistake

noun
  • An error; a blunder. 

  • A pitch which was intended to be pitched in a hard-to-hit location, but instead ends up in an easy-to-hit place. 

verb
  • To understand wrongly, taking one thing or person for another. 

mullock

noun
  • A mess; the result of a blunder. 

  • Rubbish, waste matter. 

  • Tailings: waste rock from which the wanted gold, minerals, opal, etc., has been extracted. 

  • Nonsense, rubbish. 

  • Overburden: waste material generated while searching for minerals or while mining, such as when sinking a shaft. 

verb
  • To clear waste material out of a mine. 

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