purging vs voiding

purging

noun
  • The removal of digested waste: defecation; defecation induced by laxatives. 

  • Vomiting; vomiting induced by purgatives. 

  • A removal of undesirable people. 

  • The cleansing of a device by flushing it with water, steam, or some other liquid or gas. 

  • The removal of excess humors through bloodletting, induced vomitting, etc. 

voiding

noun
  • An act by which something is voided, such as urination. 

  • That which is voided; that which is ejected or evacuated; a remnant; a fragment. 

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