betrothal vs espousal

betrothal

noun
  • The fact of being betrothed; a mutual promise, engagement, or contract for a future marriage between two people. 

  • The act of betrothing. 

espousal

noun
  • A wedding ceremony. 

  • Adoption of a plan, cause, or idea. 

  • A betrothal. 

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