fidelity vs subterfuge

fidelity

noun
  • Accuracy, or exact correspondence to some given quality or fact. 

  • Faithfulness to one's duties. 

  • Loyalty to one's spouse or partner, including abstention from cheating or extramarital affairs. 

  • The degree to which a system accurately reproduces an input. 

subterfuge

noun
  • An indirect or deceptive device or stratagem; a blind. Refers especially to war and diplomatics. 

  • Deception; misrepresentation of the true nature of an activity. 

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