fidelity vs vacillation

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. 

vacillation

noun
  • Changing location by moving back and forth. 

  • Indecision in speech or action. 

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