dead room vs mortuary

dead room and mortuary both are nouns.

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

As nouns, dead room and mortuary are synonyms defined as:

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

Other synonyms of dead room include morgue.

dead room (noun)	mortuary (noun)
a building (or room) where dead bodies are kept before burial or cremation	a building (or room) where dead bodies are kept before burial or cremation

dead room (adjective)	mortuary (adjective)
	of or relating to a funeral
	of or relating to or characteristic of death