bug-a-boo vs terror

bug-a-boo

noun
  • Any imagined fear or threat, or a fear presumed larger than it really is. 

  • A mythical, nocturnal creature; a hobgoblin. 

terror

noun
  • Something or someone that causes such fear. 

  • The action or quality of causing dread; terribleness, especially such qualities in narrative fiction. 

  • Intense dread, fright, or fear. 

  • A night terror. 

  • Terrorism. 

How often have the words bug-a-boo and terror occurred in a corpus of books? (source: Google Ngram Viewer )