postmortem examination vs autopsy

postmortem examination and autopsy both are nouns.

Word	Noun	Adjective	Verb	Adverb
postmortem examination	Yes	No	No	No
autopsy	Yes	No	Yes	No

As nouns, postmortem examination and autopsy are synonyms defined as:

postmortem examination and autopsy: an examination and dissection of a dead body to determine cause of death or the changes produced by disease

Other synonyms of postmortem examination include necropsy, PM, post-mortem, post-mortem examination, postmortem.

postmortem examination (noun)	autopsy (noun)
an examination and dissection of a dead body to determine cause of death or the changes produced by disease	an examination and dissection of a dead body to determine cause of death or the changes produced by disease

postmortem examination (verb)	autopsy (verb)
	perform an autopsy on a dead body; do a post-mortem