Open

a clear or unobstructed space or expanse of land or water

where the air is unconfined

a tournament in which both professionals and amateurs may play

information that has become public

cause to open or to become open

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

become open

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

spread out or open from a closed or folded state

make available

become available

have an opening or passage or outlet

make the opening move

afford access to

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

affording unobstructed entrance and exit

affording free passage or access

with no protection or shield

open to or in view of all

used of mouth or eyes

not having been filled

accessible to all

not defended or capable of being defended

(of textures) full of small openings or gaps

having no protecting cover or enclosure

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

not brought to a conclusion

not sealed or having been unsealed

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

ready or willing to receive favorably

open and observable

not requiring union membership

possibly accepting or permitting

affording free passage or view

openly straightforward and direct without reserve or secretiveness

ready for business