funeral home vs dead room

funeral home and dead room both are nouns.

Word	Noun	Adjective	Verb	Adverb
funeral home	Yes	No	No	No
dead room	Yes	No	No	No

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

funeral home: a mortuary where those who knew the deceased can come to pay their last respects
dead room: a building (or room) where dead bodies are kept before burial or cremation

Other hypernyms of funeral home include morgue, mortuary.

funeral home (noun)	dead room (noun)
a mortuary where those who knew the deceased can come to pay their last respects	a building (or room) where dead bodies are kept before burial or cremation