post-mortem examination vs PM

post-mortem examination and PM both are nouns.

Word	Noun	Adjective	Verb	Adverb
post-mortem examination	Yes	No	No	No
PM	Yes	No	No	No

As nouns, post-mortem examination and PM are synonyms defined as:

post-mortem examination and PM: an examination and dissection of a dead body to determine cause of death or the changes produced by disease

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

post-mortem examination (noun)	PM (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
	modulation of the phase of the carrier wave
	the person who holds the position of head of the government in the United Kingdom