subject vs open

subject and open both are nouns.

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

As adjectives, subject and open are synonyms defined as:

Other synonyms of subject include capable.

subject (noun)	open (noun)
something (a person or object or scene) selected by an artist or photographer for graphic representation	information that has become public
a branch of knowledge	a tournament in which both professionals and amateurs may play
some situation or event that is thought about	a clear or unobstructed space or expanse of land or water
the subject matter of a conversation or discussion	where the air is unconfined
(grammar) one of the two main constituents of a sentence; the grammatical constituent about which something is predicated
(logic) the first term of a proposition
a person who owes allegiance to that nation
a person who is subjected to experimental or other observational procedures; someone who is an object of investigation

subject (adjective)	open (adjective)
likely to be affected by something	ready or willing to receive favorably
being under the power or sovereignty of another or others	affording unobstructed entrance and exit; not shut or closed
possibly accepting or permitting	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

subject (verb)	open (verb)
make accountable for	make available
cause to experience or suffer or make liable or vulnerable to	become available
make subservient; force to submit or subdue	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