open

adjective

• 1allowing access, passage, or a view through an empty space; not closed or blocked up:it was a warm evening and the window was open the door was wide open the pass is kept open all year by snowplows
• (of a container) not fastened or sealed:the case burst open and its contents flew all over the place
• (of the mouth or eyes) with lips or lids parted:his eyes were open but he could see nothing
• (of a garment or its fasteners) not buttoned or fastened:his tie was knotted below the open collar of his shirt
• Phonetics (of a vowel) produced with a relatively wide opening of the mouth and the tongue kept low.
• Phonetics (of a syllable) ending in a vowel.
• (of the bowels) not constipated.
• (of a game or style of play) characterized by action that is spread out over the field.

• 2 [attributive] exposed to the air or to view; not covered:an open fire burned in the grate days without food and water in an open boat
• (of an area of land) not covered with buildings or trees:increasing numbers of new houses in open countryside
• (of a fabric) loosely knitted or woven.
• (of a team member in a game) unguarded and therefore able to receive a pass:the trick is spreading the defense so that at least one receiver gets open
• (of a goal or other object of attack in a game) unprotected; vulnerable.
• [predic.] (open to) likely to suffer from or be affected by; vulnerable or subject to:the system is open to abuse
• (of a town or city) officially declared to be undefended, and so immune under international law from bombardment.
• with the outer edges or sides drawn away from each other; unfolded:the trees had buds and a few open flowers
• (of a book or file) with the covers parted or the contents in view, allowing it to be read:she was copying verses from an open Bible
• (of a hand) not clenched into a fist.
• [as complement] damaged or injured by a deep cut in the surface:he had his arm slashed open

• 3 [predic.] (of a store, place of entertainment, etc.) officially admitting customers or visitors; available for business:the store stays open until 9 p.m.
• (of a bank account) available for transactions: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 5:30
• (of a choice, offer, or opportunity) still available; such that people can take advantage of it:the offer is open while supplies last we need to consider what options are left open

• 4(of a person) frank and communicative; not given to deception or concealment:she was open and naive I was quite open about my views
• not concealed; manifest:his eyes showed open admiration
• [attributive] (of conflict) fully developed and unconcealed:the dispute erupted into open war
• involving no concealment, restraint, or deception; welcoming discussion, criticism, and inquiry:the conclusions were reached in open discussion

• 5(of a question, case, or decision) not finally settled; still admitting of debate:students' choice of major can be kept open until the second year
• (of the mind) accessible to new ideas; unprejudiced:I’m keeping an open mind about my future
• [predic.] (open to) receptive to:the union was open to suggestions for improvements
• [predic.] (open to) admitting of; making possible:the message is open to different interpretations
• freely available or accessible; offered without restriction:the service is open to all students at the university
• (also Open) with no restrictions on those allowed to attend or participate:an open audition was announced each horse had won two open races
• (of a ticket) not restricted as to day of travel.

• 6 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.

• 7(of an electrical circuit) having a break in the conducting path.

• 8 Mathematics (of a set) not containing any of its limit points.

verb

• 1move or adjust (a door or window) so as to leave a space allowing access and view:she opened the door and went in [no object]:“Open up!” he said
• [no object] (of a door or window) be moved or adjusted to leave a space allowing access and view: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 (a mouth or eye):she opened her mouth to argue
• [no object] (of the mouth or eyes) have the lips or lids parted in this way:her eyes slowly opened
• [no object] come apart; lose or lack its protective covering:old wounds opened and I bled a little bit
• improve or make possible access to or passage through:the president announced that his government would open the border
• cause evacuation of (the bowels).
• [no object] (open onto/into) (of a room, door, or window) give access to:beautiful French doors that opened onto a balcony
• [no object] (of a panorama) come into view; spread out before someone:stop to marvel at the views that open out below
• Nautical achieve a clear view of (a place) by sailing past a headland or other obstruction:we shall open Simon’s Bay at any minute now

• 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 never opened beyond narrow points
• part the covers or display the contents of (a book or file) to read it:she opened her book at the prologue
• [no object] (open out) become wider or more spacious:the path opened out into a glade

• 3make available or more widely known:the new plan proposed to open up opportunities to immigrants the move may force the company to open up its plans for the future
• [no object] (open up) become more communicative or confiding:neither one of them had opened up to me about their troubles
• make (one’s mind or heart) more receptive or sympathetic:open your mind to what is going on around you
• (open someone (up) to) make someone vulnerable to:the process is going to open them to a legal threat

• 4establish (a new business, movement, or enterprise):they have opened a new restaurant across the street
• [no object] (of an enterprise, meeting, or event) begin or be formally established:two new restaurants open this week
• make or become officially ready for customers, visitors, or business: [with object]:one woman raised $731 by opening her home and selling coffee and tea [no object]:the mall didn’t open until 10
• take the action required to make ready for use:they have the $10 necessary to open a savings account click twice to open a file
• [no object] (of a piece of writing or music) begin:the chapter opens with a discussion of Anglo-American relations
• (open up) [no object] (of a process) start to develop:a new and dramatic phase was opening up
• officially or 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
• (of a counsel in a court of law) make a preliminary statement in (a case) before calling witnesses.
• Bridge make (the first bid) in the auction.

• 5break the conducting path of (an electrical circuit):the switch opens the motor circuit
• [no object] (of an electrical circuit or device) suffer a break in its conducting path.

noun

• 1 (Open) a championship or competition with no restrictions on who may qualify to compete:the venue for the British Open

• 2an accidental break in the conducting path for an electrical current.