apheresis vs deletion

apheresis

noun
  • The removal of blood from a patient, and the removal of certain components (such as platelets) from that blood, followed by the transfusion of the filtered blood back to the donor (patient). 

  • Elision, suppression, or complete loss of a letter or sound (syllable) from the beginning of a word, such as the development of special from especial; procope. 

deletion

noun
  • The act of deleting. 

  • An item that has been or will be deleted. 

  • An act of killing or murder. 

  • A mutation in which a gene, or other section of DNA, is removed from a chromosome. 

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