mortuary vs dead room

mortuary and dead room both are nouns.

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

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

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

Other synonyms of mortuary include morgue.

mortuary (noun)	dead room (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

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