deceased person vs decedent

deceased person and decedent both are nouns.

Word	Noun	Adjective	Verb	Adverb
deceased person	Yes	No	No	No
decedent	Yes	No	No	No

As nouns, deceased person and decedent are synonyms defined as:

Other synonyms of deceased person include dead person, dead soul, deceased, departed.

deceased person (noun)	decedent (noun)
someone who is no longer alive	someone who is no longer alive