relinquishment vs resignation

relinquishment

noun
  • The act of relinquishing something. 

resignation

noun
  • An uncomplaining acceptance of something undesirable but unavoidable. 

  • 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. 

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