open vs closed

open is a noun but closed is not a noun.

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

open (noun)	closed (noun)
information that has become public
a tournament in which both professionals and amateurs may play
a clear or unobstructed space or expanse of land or water
where the air is unconfined

open (adjective)	closed (adjective)
ready or willing to receive favorably	not open or affording passage or access
affording unobstructed entrance and exit; not shut or closed	(set theory) of an interval that contains both its endpoints
affording free passage or access	used especially of mouth or eyes
(set theory) of an interval that contains neither of its endpoints	not open
open and observable; not secret or hidden	blocked against entry
used of mouth or eyes	not open to the general public
ready for business	with shutters closed
not having been filled	requiring union membership
(of textures) full of small openings or gaps	not having an open mind
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)	closed (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