dead body vs corpse

dead body and corpse both are nouns.

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

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

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

dead body (noun)	corpse (noun)
a natural object consisting of a dead animal or person	the dead body of a human being