elision vs hemapheresis

elision

noun
  • The deliberate omission of something. 

  • The omission of a letter or syllable between two words or inside a word; sometimes marked with an apostrophe. 

  • A different mode or method of operating a computer program. 

hemapheresis

noun
  • The removal of selective components of the blood 

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