dysphemism vs expletive

dysphemism

noun
  • The use of a word or phrase carrying negative connotations or imagery (especially one that is derogatory, offensive or vulgar) to replace a (more) neutral original. 

  • A word or phrase that is used to replace another in this way. 

expletive

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. 

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

  • Marked by expletives (phrase-fillers). 

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