expletive vs oath

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). 

oath

noun
  • A curse, a curse word. 

  • A light, irreverent or insulting appeal to a deity or other entity. 

  • A solemn pledge or promise that invokes a deity, a ruler, or another entity (not necessarily present) to attest the truth of a statement or sincerity of one's desire to fulfill a contract or promise. 

  • A statement or promise which is strengthened (affirmed) by such a pledge. 

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