abdication vs resignation

abdication

noun
  • The act of abdicating; the renunciation of a high office, dignity, or trust, by its holder. 

  • The voluntary renunciation of sovereign power. 

resignation

noun
  • The act of resigning. 

  • A written or oral declaration that one resigns. 

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

  • An uncomplaining acceptance of something undesirable but unavoidable. 

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