bellow vs expletive

bellow

noun
  • The deep roar of a large animal, or any similar loud noise. 

verb
  • To shout in a deep voice. 

  • To make a loud, deep, hollow noise like the roar of an angry bull. 

expletive

adj
  • Serving to fill up, merely for effect, otherwise redundant. 

  • Marked by expletives (phrase-fillers). 

noun
  • A profane, vulgar term, notably a curse or obscene oath. 

  • A word without meaning added to fill a syntactic position. 

  • A word that adds to the strength of a phrase without affecting its meaning. 

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