What is the meaning of postmortem?

noun

• Discussion of an event after it has occurred.
  • synonyms: post-mortem
• An examination and dissection of a dead body to determine cause of death or the changes produced by disease.
  • synonyms: autopsy, necropsy, post-mortem, PM, postmortem examination, post-mortem examination

adjective

• Occurring or done after death.
  • usage: "postmortem changes"; "a postmortem examination to determine cause of death"; "postmortal wounds"
  • synonyms: postmortal
• After death or after an event.
  • usage: "a postmortem examination to determine the cause of death"; "the postmortem discussion of the President's TV address"