scoria vs waster

scoria

noun
  • The slag or dross that remains after the smelting of metal from an ore. 

  • Rough masses of rock formed by solidified lava, and which can be found around a volcano's crater. 

waster

noun
  • An item that is spoiled during its manufacture. 

  • A destroyer. 

  • An imperfection in the wick of a candle, causing it to waste. 

  • Someone or something that wastes; someone who squanders or spends extravagantly. 

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