bolk vs eructation

bolk

verb
  • To belch out; give vent to; ejaculate. 

  • To vomit; retch. 

  • To heave. 

  • To belch. 

  • To gush out. 

eructation

noun
  • The act of belching, of expelling gas from the stomach through the mouth. 

  • An erumpent blast of gas, wind, or other matter ejected from the depths of the earth. 

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