a clear or unobstructed space or expanse of land or water:
- "the concert was held in the open air"
- "camping in the open"
- "finally broke out of the forest into the open"
a tournament in which both professionals and amateurs may play
- "US Open, Swedish Open"
- "the door opens to the patio"
- "open the map"
cause to open or to become open
- "Mary opened the car door"
start to operate or function or cause to start operating or functioning
- "open a business"
- "The door opened"
begin or set in action, of meetings, speeches, recitals, etc.
- "He opened the meeting with a long speech"
make available, as of an opportunity
- "This opens up new possibilities"
- "an opportunity opened up"
have an opening or passage or outlet
- "The bedrooms open into the hall"
make the opening move, in chess
- "Kasparov opened with a standard opening"
display the contents of a file or start an application
affording unobstructed entrance and exit; not shut or closed
- "an open city"
- "an open texture"
- "an open wound"
- "open to the weather"
- "open hostility"
- "open family strife"
- "open disregard of the law"
- "an open and trusting nature"
- "open to attack"
- "an open door"
- "they left the door open"
affording free passage or access
- "open drains"
- "open ranks"
- "the road is open to traffic"
open to or in view of all
- "an open letter to the editor"
- "an open protest"
used of mouth or eyes
- "keep your eyes open"
- "his mouth slightly opened"
not having been filled
- "the job is still open"
accessible to all
- "an open economy"
- "open season"
having no protecting cover or enclosure
- "open sports cars"
- "an open fire"
- "an open boat"
- "an open newspaper"
(mathematics) of a set; containing points whose neighborhood consists of other points of the same set, or being the complement of an open set; of an interval; containing neither of its end points
not brought to a conclusion; subject to further thought
- "an open question"
not sealed or having been unsealed
- "the opened package lay on the table"
- "the letter was already open"
without undue constriction as from e.g. tenseness or inhibition
- "her natural and open response"
- "the clarity and resonance of an open tone"
relatively empty of and unobstructed by fences or hedges or headlands or shoals
- "on the open seas"
- "open waters"
- "the open countryside"
- "in open country"
- "open plans"
- "an open ballot"
sincere and free of reserve in expression
- "Please be open with me"
receptive to new ideas
- "an open mind"
- "open to new ideas"
ready for business
- "the stores are open"