barbarism vs mercilessness

barbarism

noun
  • The condition of existing barbarically. 

  • A barbaric act. 

  • An error in language use within a single word, such as a mispronunciation. 

  • A word hybridizing Ancient Greek and Latin or other heterogeneous roots. 

mercilessness

noun
  • The property of being merciless. 

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