Of, pertaining to, or providing accessibility. For example, an open file is one that can be used because a program has issued an open file command to the operating system.

1. Affording free passage or access
2. Affording unobstructed entrance and exit; not shut or closed; SYN. unfastened.
3. Not having been filled
4. Not sealed or having been unsealed; SYN. opened.
5. Not brought to a conclusion; subject to further thought; SYN. undecided, undetermined, unresolved.
6. Displayed before or in view of all
7. Unfolded
8. Not secret
9. Ready for business
10. Receptive to new ideas
11. Relatively empty of and unobstructed by fences or hedges or headlands or shoals
12. Sincere and free of reserve in expression
13. Used of mouth or eyes; SYN. opened.
14. Without undue constriction as from e.g. tenseness or inhibition
15. Accessible to all
16. Having no protecting cover or enclosure
17. Lax in enforcing laws; SYN. wide-open, lawless.
18. Not requiring union membership
19. (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.
ETYM as. open; akin to Dutch open, os. opan, German offan, Icel. opinn, Swed. öppen, Dan. aaben, and perh. to Eng. up. Related to Up, and Ope.

1. A clear or unobstructed space or expanse of land or water:; SYN. clear.
2. A tournament in which both professionals and amateurs may play.
3. Information that has become public; SYN. surface.

To make an object, such as a file, accessible.

1. To become available; SYN. open up.
2. To become open; SYN. open up.
3. To begin or set in action, of meetings, speeches, recitals, etc.
4. To cause to open or to become open; SYN. open up.
5. To display the contents of a file or start an application.
6. To have an opening or passage or outlet
7. To make available, as of an opportunity; SYN. open up.
8. To make the opening move, in chess
9. To start to operate or function or cause to start operating or functioning; SYN. open up.

1. When you open something up, you reveal what is inside so that people can see it.
2. When you open a room or building up, you unlock or open the doors so that people can enter.
3. When a new business starts, it opens up or is opened up by someone.

An unpaid credit order.

Enrollment on demand as a student in an institution of higher learning irrespective of formal qualifications

An adoption that involves contact between biological and adoptive parents and sometimes between biological parents and the adopted child

The space where air is unconfined; especially; outdoors

Set up an account (in a bank, store, etc.)

1. Any computer or peripheral design that has published specifications. A published specification lets third parties develop add-on hardware for a computer or device. Compare closed architecture (definition 1).
2. A design that provides for expansion slots on the motherboard, thereby allowing the addition of boards to enhance or customize a system. Compare closed architecture (definition 2).

An eager or warm welcome

A bar (as at a wedding reception) at which drinks are served free — compare cash bar

Advertised bidding, bidding that is not limited to specific participants

A chain of atoms in a molecule whose ends are not joined to form a ring.
An arrangement of atoms represented in a structural formula by a chain whose ends are not joined so as to form a ring.

Blank check, signed check that allows the holder of it to write in any amount of cash that they would like

Blank check, signed check that allows the holder of it to write in any amount of cash that they would like

An incomplete electrical circuit in which no current flows.
The lack of electrical contact in any part of the measuring circuit. An open circuit is usually characterized by rapid large jumps in displayed potential, followed by an off-scale reading.

A city that is not occupied or defended by military forces and that is not allowed to be bombed under international law.

See ODI.

The marking of perishable food products with a clearly readable date indicating when the food was packaged or the last date on which it should be sold or used.

See ODMA.

Freedom of access

1. The voluntary enrollment of a student in a public school other than the one assigned on the basis of residence
2. Enrollment on demand as a student in an institution of higher learning irrespective of formal qualifications

A file that can be read from, written to, or both. A program must first open a file before the file’s contents can be used, and it must close the file when done. See also open2.

The Microsoft specification for an interface between electronic banking services and Microsoft Money personal finance software. Acronym: OFC.

To start firing a weapon; SYN. fire.

Any frame in which a bowler fails to make a strike or spare; SYN. break.

A consortium of computer hardware and software manufacturers and users from industry, government, and academia that is dedicated to the advancement of multi-vendor information systems. The Open Group was formed in 1996 as a consolidation of the Open Software Foundation and X/Open Company Limited.

An informal party of people with hospitality for all comers.

An interval that does not include its endpoints; SYN. unbounded interval.

A letter of protest; addressed to one person but intended for the general public.

A control system for an operation or process in which there is no self-correcting action as there is in a closed loop

A mail server that supports mail relaying, a method used by spammers for sending junk mail.
See: mail relaying

A marriage in which the partners agree to let each other have sexual partners outside the marriage

An event in which amateurs may perform (as at a coffeehouse) usually without auditioning first

To speak; to say something.

A military formation leaving enough space between ranks to allow an inspecting officer to pass.

See OPI.

A primary in which any registered voter can vote (but must vote for candidates of only one party).

An Internet personalization and privacy specification submitted for consideration to the World Wide Web Consortium by Netscape Communications Corporation, Firefly Network, Inc., and VeriSign, Inc. Open Profiling Standard (OPS) enables users to customize online services while protecting their privacy. To achieve personalization and privacy concomitantly, OPS is based on the concept of a Personal Profile, which is stored on the individual’s computer and contains the user’s unique identification, demographic and contact data, and possibly content preferences. This information remains under the user’s control and can be released wholly or in part to the requesting site. Acronym: OPS. See also cookie, digital certificate.

Question that has not yet been answered, unsettled matter

Part of the sea that is not surrounded by land

1. A period when it is legal to kill or catch game or fish protected at other times by law
2. A time during which someone or something is the object of sustained attack or criticism

Something that is supposed to be secret but is generally known

A statement (as in mathematics) that contains at least one blank or unknown and that becomes true or false when the blank is filled or a quantity is substituted for the unknown

1. A magical command; used by Ali Baba.
2. Any very successful means of achieving a result.

Magical phrase that opens doors

A company whose workers are hired without regard to their membership in a labor union.
Factory or other business employing men and women not belonging to labor unions, as opposed to the closed shop, which employs labor unionists only.
A computer facility that is open to users and not restricted to programmers or other personnel. An open shop is one in which people can work on or attempt to solve computer problems on their own rather than handing them over to a specialist.

See OSPF.

Rear gunsight having an open notch instead of a peephole or telescope.

See OSF.

The practice of making the source code (program instructions) for a software product freely available, at no cost, to interested users and developers, even though they were not involved in creating the original product. The distributors of open source software expect and encourage users and outside programmers to examine the code in order to identify problems, and to modify the code with suggested improvements and enhancements. Widely used open source products include the Linux operating system and the Apache Web server.

A stance (as in golf) in which the forward foot is farther from the line of play than the back foot — compare closed stance

A publicly available set of specifications describing the characteristics of a hardware device or software program. Open standards are published to encourage interoperability and thereby help popularize new technologies. See also standard (definition 2).

In music, the string of an instrument played without the finger touching it, allowing it to vibrate along its entire length. This is notated by an “o” above the note. The open strings of the violin are: G3, D4, A4, and E5; of the viola: C3, G3, D4, and A4; of the cello: C2, G2, D3, and A3; and of the double bass: E1, A1, D2, and G2.

A syllable ended by a vowel or diphthong

1. In communications, a computer network designed to incorporate all devices—regardless of the manufacturer or model—that can use the same communications facilities and protocols.
2. In reference to computer hardware or software, a system that can accept add-ons produced by third-party suppliers. A system whose specifications are fully available to anyone who wants to see them.

(OSI) In computing, International Standards Organization standard, defining seven layers of communication protocols. Although OSI is an international standard, existing protocols, such as TCP/IP and IBM's System Network Architecture are more commonly used in commercial systems.

See ISO/OSI reference model.

Begin the meeting

1. To make available
2. To make plain or visible; disclose
3. To open by cutting into
4. To spread out or come into view
5. To commence firing
6. To become communicative
7. To talk freely and without inhibition.

A weave in which warp threads never come together, leaving interstices in the fabric.

Overhead wire, upper wire

Wound that has not yet coagulated, rapid flow of blood; painful memory, painful scar

Outdoor.

A public place where food and merchandise is sold; SYN. market square.

1. Perfectly simple; obvious
2. Easily settled

Lovingly, in a welcoming manner, with open arms

Of a shirt; not buttoned at the neck.

The policy of granting equal trade opportunities to all countries; SYN. open door.
Economic philosophy of equal access by all nations to another nation's markets.
The term was applied Sept 1899 by Secretary of State John Hay to the US policy toward China. Several European powers had carved out spheres of influence in China, and US and British interests were excluded from those areas. Hay called on all nations to preserve and respect China's territorial and administrative independence and integrity. The US reaffirmed its position 1931 and 1937 when Japan attacked China.

Organized to allow for contingencies: as permitting additional debt to be incurred under the original indenture subject to specified conditions; having a fluctuating capitalization of shares that are issued or redeemed at the current net asset value or at a figure in fixed ratio to this — compare closed-end

A consumer credit line that can be used up to a certain limit or paid down at any time; SYN. revolving credit, charge account credit.

A wrench having parallel jaws at fixed separation (often on both ends of the handle); SYN. tappet wrench.

1. Allowing for a spontaneous response
2. Allowing for future changes or revisions
3. Without fixed limits or restrictions

1. Having the eyes open
2. Carefully observant; discerning

Sandwich without a covering slice of bread; SYN. open sandwich.

Served without a covering layer (as of bread or pastry)

Of, relating to, or performed on a heart temporarily stopped and relieved of circulatory function and surgically opened for repair of defects or damage

Heart surgery in which the heart is opened and blood is detoured through a heart-lung machine.

Of, relating to, involving, or produced in the open-hearth process

Method of steelmaking, now largely superseded by the basic-oxygen process. It was developed in 1864 in England by German-born William and Friedrich Siemens, and improved by Pierre and Emile Martin in France in the same year. In the furnace, which has a wide, saucer-shaped hearth and a low roof, molten pig iron and scrap are packed into the shallow hearth and heated by overhead gas burners using preheated air.

A process for making steel using an open-hearth furnace.

Being or relating to a clinical trial in which the treatment given to each subject is not concealed from either the experimenters or the subject — compare double-blind, single-blind

Ready to entertain new ideas, receptive to arguments or ideas

State of being ready to accept new ideas

Pollinated by natural agencies (as wind or insects) without human intervention

Stork with a grooved bill whose upper and lower parts touch only at the base and tip.

(Of mines and mining) Worked from the exposed surface; SYN. opencut, strip.

Or open-pit mining or strip mining; Mining at the surface rather than underground. Coal, iron ore, and phosphates are often extracted by opencast mining. Often the mineral deposit is covered by soil, which must first be stripped off, usually by large machines such as walking draglines and bucket-wheel excavators. The ore deposit is then broken up by explosives.
One of the largest excavations in the world has been made by opencast mining at the Bingham Canyon copper mine in Utah, US, measuring 790 m/2,590 ft deep and 3.7 km/2.3 mi across.

An open source artificial intelligence platform. OpenCyc forms the foundation of knowledge-dependent applications such as speech understanding, database integration, and e-mail routing and prioritizing. OpenCyc development is administered through OpenCyc.org.

An object-oriented application programming interface (API) that enables multiple independent programs (component software) on several platforms to work together on a single document (compound document). Similar to OLE, OpenDoc allows images, sound, video, other documents, and other files to be embedded or linked to the document. OpenDoc is supported by an alliance that includes Apple, IBM, the Object Management Group, and the X Consortium. See also application programming interface, component software. Compare ActiveX, OLE.

Made open or clear

Revealed oneself, disclosed everything

1. A hand tool used for opening sealed containers (bottles or cans).
2. The first event in a series:

An industry standard application programming interface (API) for 3D graphics rendering and 3D hardware acceleration. OpenGL is cross-platform and is available for all major operating systems.

A series of online security challenges organized by eWeek magazine.

Generous, munificent

1. Candidly straightforward; frank
2. Responsive to emotional appeal
3. Freely communicative; candidly straightforward

First or beginning

1. An open or empty space in or between things; SYN. gap.
2. A vacant or unobstructed space
3. A ceremony accompanying the start of some enterprise.
4. Opportunity especially for employment or promotion
5. The act of opening something
6. The first performance (as of a theatrical production); SYN. opening night, curtain raising.
7. The initial part of the introduction
8. Becoming open or being made open

Balance of an account at its start, amount in an account when opened

The first line of a piece of writing (as a newspaper story).

First night that something is open to the public

Introductory speech

ETYM AS. openlice.
In an open way.

1. Clamorous, vociferous
2. Having the mouth wide open
3. Struck with amazement or wonder

An international organization of hardware and software developers for promoting the use of the MPEG standards. Acronym: OM-1. See also MPEG.

1. Characterized by an attitude of ready accessibility, esp. about one's actions or purposes; not secretive.
2. Without obstructions to passage or view.

Open source implementation of the Pretty Good Privacy (PGP) encryption scheme.

A woodworking plane designed to cut rabbets; SYN. rabbet plane.

A free version of the Secure Shell (SSH).
SSH is a set of protocols and tools that provides more secure replacements to Telnet, File Transfer Protocol (FTP), and other UNIX utilities. OpenSSH is a free version of SSH developed mainly by the OpenBSD Project. It is available for a variety of UNIX/Linux plat-forms and also for Mac OS X. To keep OpenSSH “open,” the project had to remove some features and support for patented encryption technologies such as International Data Encryption Algorithm (IDEA). OpenSSH nevertheless supports a wide variety of encryption schemes, including Triple DES (3DES), Advanced Encryption Standard (AES), Blowfish, CAST128, and Rivest-Shamir-Adleman (RSA).

A free version of Secure Sockets Layer (SSL).
SSL is a protocol for establishing a secure communications channel and is widely used on the Internet for encrypting e-business and e-commerce traffic. OpenSSL is an open source toolkit primarily used for implementing SSL on the Apache Web server platform. OpenSSL also includes a library of cryptographic functions and supports the Internet standard Transport Layer Security (TLS) protocol defined in RFC 2246.

Systems that conform to Open Systems Interconnection or POSIX standards. Unix was the original basis of open systems and most non-proprietary open systems still use this operating system.
The term is also used more loosely to describe any system that can communicate with other systems and to describe other standards, such as MS-DOS and Windows. Open systems were developed partly to make better communication possible, but also to reduce users' dependence on (and lock-in to) suppliers of proprietary systems.

OpenTag—A method for inserting XML tags in text to allow the extraction, translation, and re-insertion of translated material.

A collaborative initiative by Microsoft and Adobe to unify support for Microsoft TrueType and Adobe PostScript Type 1 fonts. The OpenType font format enables font creators and users to work with the font type that best suits their needs without having to worry about whether the font is based on TrueType or PostScript technology. Also called: TrueType Open version 2. See also PostScript font, TrueType.

Ornamental work (such a embroidery or latticework) having a pattern of openings.