evacuation vs purging

evacuation

noun
  • The act of emptying, clearing of the contents, or discharging, including creating a vacuum. 

  • Abolition; nullification. 

  • Voidance of any matter by the natural passages of the body or by an artificial opening; defecation; also, a diminution of the fluids of an animal body by cathartics, venesection, or other means. 

  • The act of evacuating; leaving a place in an orderly fashion, especially for safety. 

  • Withdrawal of troops or civils from a town, country, fortress, etc. 

  • That which is evacuated or discharged; especially, a discharge by stool or other natural means. 

purging

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

  • Vomiting; vomiting induced by purgatives. 

  • A removal of undesirable people. 

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

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

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