constancy vs dirty pool

constancy

noun
  • The quality of being constant; steadiness or faithfulness in action, affections, purpose, etc. 

  • An unchanging quality or characteristic of a person or thing. 

dirty pool

noun
  • Foul play, misconduct, underhandedness. 

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