adherence vs zeal

adherence

noun
  • Faithful support for some cause. 

  • An extent to which a patient continues an agreed treatment plan. 

  • The fulfilment of the legal obligation of residing with wife or husband. 

  • A close physical union of two objects. 

zeal

noun
  • The fervour or tireless devotion for a person, cause, or ideal and determination in its furtherance; diligent enthusiasm; powerful interest. 

  • The collective noun for a group of zebras. 

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