dead-air space vs area

dead-air space and area both are nouns.

Word	Noun	Adjective	Verb	Adverb
dead-air space	Yes	No	No	No
area	Yes	No	No	No

As nouns, area is a hypernym of dead-air space; that is, area is a word with a broader meaning than dead-air space:

dead-air space (noun)	area (noun)
an unventilated area where no air circulates	a part of a structure having some specific characteristic or function
	the extent of a 2-dimensional surface enclosed within a boundary
	a part of an animal that has a special function or is supplied by a given artery or nerve
	a subject of study
	a particular geographical region of indefinite boundary (usually serving some special purpose or distinguished by its people or culture or geography)
	a particular environment or walk of life