resignation vs unification

resignation

noun
  • A written or oral declaration that one resigns. 

  • The form by which a vassal returns the feu into the hands of a superior. 

  • The act of resigning. 

  • An uncomplaining acceptance of something undesirable but unavoidable. 

unification

noun
  • Given two terms, their join with respect to a specialisation order. 

  • The act of unifying. 

  • The state of being unified. 

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