dead body vs carcass

dead body and carcass both are nouns.

Word	Noun	Adjective	Verb	Adverb
dead body	Yes	No	No	No
carcass	Yes	No	No	No

As nouns, carcass is a hyponym of dead body; that is, carcass is a word with a more specific, narrower meaning than dead body:

dead body: a natural object consisting of a dead animal or person
carcass: the dead body of an animal especially one slaughtered and dressed for food

Other hyponyms of dead body include kill, carcase, carrion, roadkill, cadaver, clay, corpse, remains, stiff, mummy.

dead body (noun)	carcass (noun)
a natural object consisting of a dead animal or person	the dead body of an animal especially one slaughtered and dressed for food