crematorium vs dead room

crematorium and dead room both are nouns.

Word	Noun	Adjective	Verb	Adverb
crematorium	Yes	No	No	No
dead room	Yes	No	No	No

As nouns, dead room is a hypernym of crematorium; that is, dead room is a word with a broader meaning than crematorium:

crematorium: a mortuary where corpses are cremated
dead room: a building (or room) where dead bodies are kept before burial or cremation

Other hypernyms of crematorium include morgue, mortuary.

crematorium (noun)	dead room (noun)
a furnace where a corpse can be burned and reduced to ashes	a building (or room) where dead bodies are kept before burial or cremation
a mortuary where corpses are cremated