bogle vs bugbear

bogle

noun
  • A goblin; a frightful spectre or phantom; a bogy or bugbear. 

bugbear

noun
  • A source of dread; resentment; or irritation. 

  • An ongoing problem; a recurring obstacle or adversity. 

verb
  • To alarm with idle phantoms. 

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