"he climbed through the open window"

• (of a container) not fastened or sealed

  "the case burst open and its contents flew all over the place"

• (of a garment or its fastenings) not done up

  "his tie was knotted below the open collar of his shirt"

• (of the mouth or eyes) with lips or lids parted

  "his eyes were open but he could see nothing"

• (of a fabric) loosely knitted or woven
• (of the bowels) not constipated

"an open fire burned in the grate"

• (of land) not covered with buildings or trees

  "the plans allow increasing numbers of new houses in open countryside"

• damaged by a deep cut in the surface

  "he had his arm slashed open"

• likely to suffer from or be affected by; vulnerable or subject to

  "the system is open to abuse"

• (of a goalmouth or other object of attack in a game) unprotected by defenders
• (of a town or city) officially declared to be undefended, and so immune under international law from bombardment

"the trees had buds and a few open flowers"

• (of a book or file) with the covers parted allowing it to be read

  "she was copying verses from an open Bible"

• (of a hand) not clenched into a fist

"the shop stays open until 9 p.m"

• (of a bank account) available for transactions

  "I withdrew all my money except the minimum required to keep the account open"

• (of a phone line) ready to take calls

  "our free advice line is open from 8.30 to 17.30"

"the service is open to all students"

• (of an offer or opportunity) still available

  "the offer is open while stocks last"

• with no restrictions on those allowed to participate

  "open discussion meetings"

• (of a victor) having won an open competition

  "an Open champion"

• (of a ticket) not restricted as to day of travel

  "I have an open ticket, so I can travel any day I like"

• (of a cheque) not crossed
• (of a set) not containing any of its limit points

"she behaved in an open and cheerful manner"

• not concealed

  "his eyes showed open admiration as they swept over her"

• (of conflict) fully developed and unconcealed

  "the dispute erupted into open war"

• welcoming public discussion, criticism, and inquiry

  "the party's commitment to open government"

• (of a game or style of play) characterized by action which is spread out over the field

  "both sides played fast, open rugby to produce a high-scoring game"

"students' choice of degree can be kept open until the second year"

• (of the mind) accessible to new ideas

  "I'm keeping an open mind about my future"

• receptive to

  "the union was open to suggestions for improvements"

• admitting of; making possible

  "the message is open to different interpretations"

• (of a note) sounded from an open string or pipe
• (of a pipe) unstopped at each end

• (of a syllable) ending in a vowel

"she opened the door and went in"

• (of a door or window) be moved to leave a space allowing access

  "the door opened and a man came out"

• undo or remove the lid, cover, or fastening of (a container, package, letter, etc.) to get access to the contents

  "he opened a bottle inexpertly, spilling some of the wine"

• part the lips or lids of (one's mouth or eye)

  "she opened her mouth to argue"

• (of the mouth or eyes) have the lips or lids parted

  "her eyes slowly opened"

• come apart; lose or lack its protective covering

  "old wounds opened and I bled a little bit"

• cause evacuation of (the bowels)

"the eagle opened its wings and circled up into the air"

• part the covers of (a book or file) to read it

  "she opened her book at the prologue"

• (of a prospect) extend into view

  "stop to marvel at the views that open out below"

• achieve a clear view of (a place) by sailing past a headland or other obstruction

  "we shall open Torbay shortly"

"she raised £731 by opening her home and selling coffee and tea"

• be made ready for customers, visitors, or business

  "the shops didn't open until 10"

• ceremonially declare (a building, road, etc.) to be completed and ready for use

  "we will have to wait until a new bypass is opened before we can tackle the problem of congestion"

"she began to teach and opened her own school"

• (of an event or a new business or enterprise) be formally established or started

  "two new restaurants open this week"

• take the action required to begin using

  "they have the £10 necessary to open a savings account"

"a civil war there has opened the possibility of a peace treaty with the Federation"

"the chapter opens with a discussion of Anglo-Irish relations"

• (of a counsel in a law court) make a preliminary statement in a case before calling witnesses

  "Comyn opened for the plaintiff"

• make (the first bid) in the auction

  "West opened 2NT"

"the switch opens the motor circuit"

• (of an electric circuit or device) suffer a break in its conducting path

  "the problem was caused when a switch opened at the substation"

"guests were sitting in the open on the terrace"

• not subject to concealment; made public

  "we have never let our dislike for him come into the open"

"his victory in the 2003 Australian Open"