The Collaborative International Dictionary of English v.0.48:

Autopsy \Au"top*sy\, n. [Gr. ?, fr. ? seen by one's self; ? self
   + ? seen: cf. F. autopsie. See Optic, a.]
   1. Personal observation or examination; seeing with one's own
      eyes; ocular view.
      [1913 Webster]

            By autopsy and experiment.            --Cudworth.
      [1913 Webster]

   2. (Med.) Dissection of a dead body, for the purpose of
      ascertaining the cause, seat, or nature of a disease; a
      post-mortem examination.
      [1913 Webster] Autoptic

WordNet (r) 3.0 (2006):

autopsy
    n 1: an examination and dissection of a dead body to determine
         cause of death or the changes produced by disease [syn:
         autopsy, necropsy, postmortem, post-mortem, PM,
         postmortem examination, post-mortem examination]
    v 1: perform an autopsy on a dead body; do a post-mortem

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "autopsy":
   canvass, check, check out, check over, check up on, coroner,
   examine, give an examination, go over, inquest, inspect, look at,
   look over, medical examiner, monitor, mortality committee,
   necropsy, necroscopy, observe, overhaul, overlook, pass over,
   pass under review, peer at, peruse, pore over, post, postmortem,
   postmortem examination, review, run over, scan, scrutinize,
   set an examination, size, size up, study, survey, take stock of,
   take the measure