earthhole vs rift

earthhole

noun
  • A hole or cavern in the earth; a cave. 

rift

noun
  • A chasm or fissure. 

  • A break in the clouds, fog, mist etc., which allows light through. 

  • A shallow place in a stream; a ford. 

verb
  • To form a rift; to split open. 

  • To belch. 

  • To cleave; to rive; to split. 

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