Open

not defended or capable of being defended

possibly accepting or permitting

with no protection or shield

not sealed or having been unsealed

affording free passage or view

used of mouth or eyes

open and observable; not secret or hidden

affording unobstructed entrance and exit; not shut or closed

(of textures) full of small openings or gaps

openly straightforward and direct without reserve or secretiveness

not brought to a conclusion; subject to further thought

affording free passage or access

accessible to all

having no protecting cover or enclosure

open to or in view of all

without undue constriction as from e.g. tenseness or inhibition

not having been filled

not requiring union membership

ready for business

ready or willing to receive favorably

(set theory) of an interval that contains neither of its endpoints

where the air is unconfined

a clear or unobstructed space or expanse of land or water

information that has become public

a tournament in which both professionals and amateurs may play

spread out or open from a closed or folded state

become available

become open

make available

start to operate or function or cause to start operating or functioning

afford access to

cause to open or to become open

begin or set in action, of meetings, speeches, recitals, etc.

make the opening move

display the contents of a file or start an application as on a computer

have an opening or passage or outlet