aposiopesis vs oxymoron

aposiopesis

noun
  • An abrupt breaking-off in speech, often indicated in print using an ellipsis (…) or an em dash (—). 

oxymoron

noun
  • A figure of speech in which two words or phrases with opposing meanings are used together intentionally for effect. 

  • A contradiction in terms. 

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