open vs area

open and area both are nouns.

Word	Noun	Adjective	Verb	Adverb
open	Yes	Yes	Yes	No
area	Yes	No	No	No

As nouns, area is a hypernym of open; that is, area is a word with a broader meaning than open:

open: a clear or unobstructed space or expanse of land or water
area: a particular geographical region of indefinite boundary (usually serving some special purpose or distinguished by its people or culture or geography)

Other hypernyms of open include country.

open (noun)	area (noun)
information that has become public	a part of a structure having some specific characteristic or function
a tournament in which both professionals and amateurs may play	the extent of a 2-dimensional surface enclosed within a boundary
a clear or unobstructed space or expanse of land or water	a part of an animal that has a special function or is supplied by a given artery or nerve
where the air is unconfined	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

open (adjective)	area (adjective)
ready or willing to receive favorably
affording unobstructed entrance and exit; not shut or closed
affording free passage or access
(set theory) of an interval that contains neither of its endpoints
open and observable; not secret or hidden
used of mouth or eyes
ready for business
not having been filled
(of textures) full of small openings or gaps
openly straightforward and direct without reserve or secretiveness
not requiring union membership
open to or in view of all
possibly accepting or permitting
without undue constriction as from e.g. tenseness or inhibition
having no protecting cover or enclosure
affording free passage or view
with no protection or shield
accessible to all
not sealed or having been unsealed
not brought to a conclusion; subject to further thought
not defended or capable of being defended

open (verb)	area (verb)
make available
become available
make the opening move
cause to open or to become open
become open
spread out or open from a closed or folded state
display the contents of a file or start an application as on a computer
afford access to
start to operate or function or cause to start operating or functioning
begin or set in action, of meetings, speeches, recitals, etc.
have an opening or passage or outlet