erroneously vs unfortunately

erroneously

adv
  • In an erroneous manner. 

  • Incorrectly. 

unfortunately

adv
  • Happening through bad luck, or because of some unfortunate event. 

  • Used (as a parenthetical word) to express disappointment, compassion, sorrow, regret or grief. 

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