belching vs eructation

belching

noun
  • The act of producing a belch. 

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 belching and eructation occurred in a corpus of books? (source: Google Ngram Viewer )