kiasi vs pitiless

kiasi

adj
  • Unwilling to take a chance for fear that something bad or unfavourable will happen; cowardly. 

noun
  • A kiasi person. 

pitiless

adj
  • having, or showing, no pity; merciless, ruthless 

  • having no kindly feelings; unkind 

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