anchoress vs lone wolf

anchoress

noun
  • A female anchorite. A woman who chooses to withdraw from the world to live a solitary life of prayer and contemplation. 

  • An anchorwoman. 

lone wolf

noun
  • A person who avoids the company of others; a loner; an independent or solitary person. 

  • A wolf that is not part of a pack. 

  • A criminal who acts alone, not as part of a group. 

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