mullock vs scrapyard

mullock

noun
  • Rubbish, waste matter. 

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

  • Nonsense, rubbish. 

  • A mess; the result of a blunder. 

  • 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. 

scrapyard

noun
  • A junkyard, a place where scrap is stored, discarded or resold. 

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