open

adjective

• 1allowing access, passage, or a view through an empty space; not closed or blocked:he climbed through the open window she was put in a cubicle with the curtains left open the pass is kept open by snowploughs
• (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 [as complement]:the boy’s mouth dropped open in shock
• (of the bowels) not constipated.

• 2 [attributive] exposed to the air or to view; not covered:an open fire burned in the grate he crossed the ocean in an open boat
• (of land) not covered with buildings or trees:the plans allow increasing numbers of new houses in open countryside
• [as complement] damaged by a deep cut in the surface:he had his arm slashed open
• (open to) 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.

• 3with the outer edges or sides drawn away from each other; unfolded or spread out: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.
• (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

• 4 [predic.] (of a business, place of entertainment, etc.) admitting customers or visitors; available for business:the shop stays open until 9 p.m. parts of the castle are open to the public
• (of a bank account) available for transactions: I withdrew all my money except the minimum required to keep the account open
• (of a telephone line) ready to take calls: our free advice line is open from 8.30 to 17.30

• 5freely available or accessible; unrestricted:the service is open to all students
• (of an offer or opportunity) still available:the offer is open while stocks last we need to consider what options are left open
• (also Open) with no restrictions on those allowed to participate:open discussion meetings each horse had won two open races
• (also Open) (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
• British (of a cheque) not crossed.
• Mathematics (of a set) not containing any of its limit points.

• 6not concealing one’s thoughts or feelings; frank and communicative:she behaved in an open and cheerful manner I was quite open about my views
• not concealed:his eyes showed open admiration as they swept over her
• [attributive] (of conflict) fully developed and unconcealed:the dispute erupted into open war
• welcoming public discussion, criticism, and enquiry:the party’s commitment to open government

• 7(of a matter or decision) not finally settled; still admitting of debate: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
• (open to) receptive to:the union was open to suggestions for improvements
• (open to) admitting of; making possible:the message is open to different interpretations

• 8 Phonetics (of a vowel) produced with a relatively wide opening of the mouth and the tongue kept low.
• (of a syllable) ending in a vowel.

• 9 Music (of a string) allowed to vibrate along its whole length.
• (of a pipe) unstopped at each end.
• (of a note) sounded from an open string or pipe.

• 10(of an electric circuit) having a break in the conducting path.

• 11(of a fabric) loosely knitted or woven.

verb

• 1move (a door or window) so as to leave a space allowing access and vision:she opened the door and went in [no object, in imperative]:‘Open up!’ he said
• [no object] (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 can we open the presents now?
• part the lips or lids of (one’s mouth or eye): she opened her mouth to argue
• [no object] (of the mouth or eyes) have the lips or lids parted:her eyes slowly opened
• [no object] come apart; lose or lack its protective covering:old wounds opened and I bled a little bit
• [no object] (open on to/into) (of a room, door, or window) give access to:the kitchen opened into a pleasant sitting room
• cause evacuation of (the bowels).

• 2unfold or be unfolded; spread out: [with object]:the eagle opened its wings and circled up into the air the tail looks like a fan when it is opened out fully [no object]:the flowers only open during bright weather
• [with object] part the covers of (a book or file) to read it:she opened her book at the prologue
• [no object] (open out) become wider:the path opened out into a glade
• [no object, with adverbial] (of a prospect) extend into view:stop to marvel at the views that open out below
• [with object] Nautical achieve a clear view of (a place) by sailing past a headland or other obstruction:we shall open Torbay shortly

• 3make or become formally ready for customers, visitors, or business: [with obj.]:she raised $731 by opening her home and selling coffee and tea [no object]:the shops didn’t open until 10
• [with object] ceremonially declare (a building, road, etc.) to be completed and ready for use:the Queen opened the power plant on 17 October 1956
• [with object] make possible access to or passage through:the President announced that his government would open the border

• 4formally establish or begin (a new business, movement, or enterprise):she began to teach and opened her own school we opened up a branch in Madrid
• [no object] (of an enterprise, meeting, or event) begin or be formally established:two new restaurants open this week
• take the action required to begin using:they have the £10 necessary to open a savings account click twice to open a file for the software selected
• [no object] (of a piece of writing or music) begin:the chapter opens with a discussion of Anglo-Irish relations
• [no object] (open up) (of a process) start to develop:a new and dramatic phase was opening up
• (of a counsel in a law court) make a preliminary statement in (a case) before calling witnesses: Bernard had opened the case [no object]:Comyn opened for the plaintiff
• Cricketanother term for open the batting below.
• Bridge make (the first bid) in the auction: West opened 2NT [no object]:do not open with fewer than twelve points

• 5make available or more widely known:new technologies open up thousands of different opportunities
• [no object] (open out/up) become more communicative or confiding:he was very reserved and only opened out to her slowly
• make (one’s mind) more receptive or sympathetic:open your mind to what is going on around you
• (open someone to/up to) make someone vulnerable to:the process is going to open them to a legal threat

• 6break the conducting path of (an electric circuit): the switch opens the motor circuit
• [no object] (of an electric circuit or device) suffer a break in its conducting path: the problem was caused when a switch opened at the substation

noun

• 1 [mass noun] (the open) outdoors or in the countryside:guests were sitting in the open on the terrace
• (in/into the open) not subject to concealment; made public:we have never let our dislike for him come into the open

• 2 (Open) a championship or competition with no restrictions on who may compete:his victory in the 2003 Australian Open

• 3an accidental break in the conducting path for an electric current.