necropsy vs postmortem

necropsy and postmortem both are nouns.

Word	Noun	Adjective	Verb	Adverb
necropsy	Yes	No	No	No
postmortem	Yes	Yes	No	No

As nouns, necropsy and postmortem are synonyms defined as:

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

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

necropsy (noun)	postmortem (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
	discussion of an event after it has occurred

necropsy (adjective)	postmortem (adjective)
	occurring or done after death
	after death or after an event