bowk vs rift

bowk

verb
  • To belch, to burp. 

  • To vomit. 

rift

verb
  • To belch. 

  • To form a rift; to split open. 

  • To cleave; to rive; to split. 

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

  • A chasm or fissure. 

  • A shallow place in a stream; a ford. 

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