apheresis vs impropriety

apheresis

noun
  • 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. 

  • 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). 

impropriety

noun
  • Improper language. 

  • The condition of being improper. 

  • An improper act. 

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