necropsy vs post mortem

necropsy

noun
  • The pathological examination of a corpse, particularly to determine cause of death. 

verb
  • The act of performing a necropsy. 

post mortem

noun
  • An investigation of a corpse to determine the cause of death. 

  • Any investigation after the conclusion of an activity, particularly when said activity produces an unwanted outcome. 

adv
  • Occurring after death. 

adj
  • Having been inflicted or having occurred after death. 

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