Search Result for "open": 
Wordnet 3.0

NOUN (4)

1. a clear or unobstructed space or expanse of land or water;
- Example: "finally broke out of the forest into the open"
[syn: open, clear]

2. where the air is unconfined;
- Example: "he wanted to get outdoors a little"
- Example: "the concert was held in the open air"
- Example: "camping in the open"
[syn: outdoors, out-of-doors, open air, open]

3. a tournament in which both professionals and amateurs may play;

4. information that has become public;
- Example: "all the reports were out in the open"
- Example: "the facts had been brought to the surface"
[syn: open, surface]


VERB (11)

1. cause to open or to become open;
- Example: "Mary opened the car door"
[syn: open, open up]

2. start to operate or function or cause to start operating or functioning;
- Example: "open a business"
[syn: open, open up]

3. become open;
- Example: "The door opened"
[syn: open, open up]

4. begin or set in action, of meetings, speeches, recitals, etc.;
- Example: "He opened the meeting with a long speech"

5. spread out or open from a closed or folded state;
- Example: "open the map"
- Example: "spread your arms"
[syn: unfold, spread, spread out, open]

6. make available;
- Example: "This opens up new possibilities"
[syn: open, open up]

7. become available;
- Example: "an opportunity opened up"
[syn: open, open up]

8. have an opening or passage or outlet;
- Example: "The bedrooms open into the hall"

9. make the opening move;
- Example: "Kasparov opened with a standard opening"

10. afford access to;
- Example: "the door opens to the patio"
- Example: "The French doors give onto a terrace"
[syn: afford, open, give]

11. display the contents of a file or start an application as on a computer;


ADJECTIVE (21)

1. affording unobstructed entrance and exit; not shut or closed;
- Example: "an open door"
- Example: "they left the door open"
[syn: open, unfastened]

2. affording free passage or access;
- Example: "open drains"
- Example: "the road is open to traffic"
- Example: "open ranks"

3. with no protection or shield;
- Example: "the exposed northeast frontier"
- Example: "open to the weather"
- Example: "an open wound"
[syn: exposed, open]

4. open to or in view of all;
- Example: "an open protest"
- Example: "an open letter to the editor"

5. used of mouth or eyes;
- Example: "keep your eyes open"
- Example: "his mouth slightly opened"
[syn: open, opened]

6. not having been filled;
- Example: "the job is still open"

7. accessible to all;
- Example: "open season"
- Example: "an open economy"

8. not defended or capable of being defended;
- Example: "an open city"
- Example: "open to attack"
[syn: assailable, undefendable, undefended, open]

9. (of textures) full of small openings or gaps;
- Example: "an open texture"
- Example: "a loose weave"
[syn: loose, open]

10. having no protecting cover or enclosure;
- Example: "an open boat"
- Example: "an open fire"
- Example: "open sports cars"

11. (set theory) of an interval that contains neither of its endpoints;

12. not brought to a conclusion; subject to further thought;
- Example: "an open question"
- Example: "our position on this bill is still undecided"
- Example: "our lawsuit is still undetermined"
[syn: open, undecided, undetermined, unresolved]

13. not sealed or having been unsealed;
- Example: "the letter was already open"
- Example: "the opened package lay on the table"
[syn: open, opened]

14. without undue constriction as from e.g. tenseness or inhibition;
- Example: "the clarity and resonance of an open tone"
- Example: "her natural and open response"

15. ready or willing to receive favorably;
- Example: "receptive to the proposals"
[syn: receptive, open]

16. open and observable; not secret or hidden;
- Example: "an overt lie"
- Example: "overt hostility"
- Example: "overt intelligence gathering"
- Example: "open ballots"
[syn: overt, open]

17. not requiring union membership;
- Example: "an open shop employs nonunion workers"

18. possibly accepting or permitting;
- Example: "a passage capable of misinterpretation"
- Example: "open to interpretation"
- Example: "an issue open to question"
- Example: "the time is fixed by the director and players and therefore subject to much variation"
[syn: capable, open, subject]

19. affording free passage or view;
- Example: "a clear view"
- Example: "a clear path to victory"
- Example: "open waters"
- Example: "the open countryside"
[syn: clear, open]

20. openly straightforward and direct without reserve or secretiveness;
- Example: "his candid eyes"
- Example: "an open and trusting nature"
- Example: "a heart-to-heart talk"
[syn: candid, open, heart-to-heart]

21. ready for business;
- Example: "the stores are open"


The Collaborative International Dictionary of English v.0.48:

Open \O"pen\, a. [AS. open; akin to D. open, OS. opan, G. offan, Icel. opinn, Sw. ["o]ppen, Dan. aaben, and perh. to E. up. Cf. Up, and Ope.] 1. Free of access; not shut up; not closed; affording unobstructed ingress or egress; not impeding or preventing passage; not locked up or covered over; -- applied to passageways; as, an open door, window, road, etc.; also, to inclosed structures or objects; as, open houses, boxes, baskets, bottles, etc.; also, to means of communication or approach by water or land; as, an open harbor or roadstead. [1913 Webster] Through the gate, Wide open and unguarded, Satan passed. --Milton [1913 Webster] Note: Also, figuratively, used of the ways of communication of the mind, as by the senses; ready to hear, see, etc.; as, to keep one's eyes and ears open. [1913 Webster] His ears are open unto their cry. --Ps. xxxiv. 15. [1913 Webster] 2. Free to be used, enjoyed, visited, or the like; not private; public; unrestricted in use; as, an open library, museum, court, or other assembly; liable to the approach, trespass, or attack of any one; unprotected; exposed. [1913 Webster] If Demetrius . . . have a matter against any man, the law is open and there are deputies. --Acts xix. 33. [1913 Webster] The service that I truly did his life, Hath left me open to all injuries. --Shak. [1913 Webster] 3. Free or cleared of obstruction to progress or to view; accessible; as, an open tract; the open sea. [1913 Webster] 4. Not drawn together, closed, or contracted; extended; expanded; as, an open hand; open arms; an open flower; an open prospect. [1913 Webster] Each, with open arms, embraced her chosen knight. --Dryden. [1913 Webster] 5. Hence: (a) Without reserve or false pretense; sincere; characterized by sincerity; unfeigned; frank; also, generous; liberal; bounteous; -- applied to personal appearance, or character, and to the expression of thought and feeling, etc. [1913 Webster] With aspect open, shall erect his head. --Pope. [1913 Webster] The Moor is of a free and open nature. --Shak. [1913 Webster] The French are always open, familiar, and talkative. --Addison. [1913 Webster] (b) Not concealed or secret; not hidden or disguised; exposed to view or to knowledge; revealed; apparent; as, open schemes or plans; open shame or guilt; open source code. [1913 Webster +PJC] His thefts are too open. --Shak. [1913 Webster] That I may find him, and with secret gaze Or open admiration him behold. --Milton. [1913 Webster] 6. Not of a quality to prevent communication, as by closing water ways, blocking roads, etc.; hence, not frosty or inclement; mild; -- used of the weather or the climate; as, an open season; an open winter. --Bacon. [1913 Webster] 7. Not settled or adjusted; not decided or determined; not closed or withdrawn from consideration; as, an open account; an open question; to keep an offer or opportunity open. [1913 Webster] 8. Free; disengaged; unappropriated; as, to keep a day open for any purpose; to be open for an engagement. [1913 Webster] 9. (Phon.) (a) Uttered with a relatively wide opening of the articulating organs; -- said of vowels; as, the [aum]n f[aum]r is open as compared with the [=a] in s[=a]y. (b) Uttered, as a consonant, with the oral passage simply narrowed without closure, as in uttering s. [1913 Webster] 10. (Mus.) (a) Not closed or stopped with the finger; -- said of the string of an instrument, as of a violin, when it is allowed to vibrate throughout its whole length. (b) Produced by an open string; as, an open tone. [1913 Webster] The open air, the air out of doors. Open chain. (Chem.) See Closed chain, under Chain. Open circuit (Elec.), a conducting circuit which is incomplete, or interrupted at some point; -- opposed to an uninterrupted, or closed circuit. Open communion, communion in the Lord's supper not restricted to persons who have been baptized by immersion. Cf. Close communion, under Close, a. Open diapason (Mus.), a certain stop in an organ, in which the pipes or tubes are formed like the mouthpiece of a flageolet at the end where the wind enters, and are open at the other end. Open flank (Fort.), the part of the flank covered by the orillon. Open-front furnace (Metal.), a blast furnace having a forehearth. Open harmony (Mus.), harmony the tones of which are widely dispersed, or separated by wide intervals. Open hawse (Naut.), a hawse in which the cables are parallel or slightly divergent. Cf. Foul hawse, under Hawse. Open hearth (Metal.), the shallow hearth of a reverberatory furnace. Open-hearth furnace, a reverberatory furnace; esp., a kind of reverberatory furnace in which the fuel is gas, used in manufacturing steel. Open-hearth process (Steel Manuf.), a process by which melted cast iron is converted into steel by the addition of wrought iron, or iron ore and manganese, and by exposure to heat in an open-hearth furnace; -- also called the Siemens-Martin process, from the inventors. Open-hearth steel, steel made by an open-hearth process; -- also called Siemens-Martin steel. Open newel. (Arch.) See Hollow newel, under Hollow. Open pipe (Mus.), a pipe open at the top. It has a pitch about an octave higher than a closed pipe of the same length. Open-timber roof (Arch.), a roof of which the constructional parts, together with the under side of the covering, or its lining, are treated ornamentally, and left to form the ceiling of an apartment below, as in a church, a public hall, and the like. Open vowel or Open consonant. See Open, a., 9. [1913 Webster] Note: Open is used in many compounds, most of which are self-explaining; as, open-breasted, open-minded. [1913 Webster] Syn: Unclosed; uncovered; unprotected; exposed; plain; apparent; obvious; evident; public; unreserved; frank; sincere; undissembling; artless. See Candid, and Ingenuous. [1913 Webster]
The Collaborative International Dictionary of English v.0.48:

Open \O"pen\, n. Open or unobstructed space; clear land, without trees or obstructions; open ocean; open water. "To sail into the open." --Jowett (Thucyd.). [1913 Webster] Then we got into the open. --W. Black. [1913 Webster] In open, In th open, in full view; without concealment; openly. [Obs.] --Beau. & Fl. [1913 Webster +PJC]
The Collaborative International Dictionary of English v.0.48:

Open \O"pen\ v. t. [imp. & p. p. Opened; p. pr. & vb. n. Opening.] [AS. openian. See Open,a.] 1. To make or set open; to render free of access; to unclose; to unbar; to unlock; to remove any fastening or covering from; as, to open a door; to open a box; to open a room; to open a letter. [1913 Webster] And all the windows of my heart I open to the day. --Whittier. [1913 Webster] 2. To spread; to expand; as, to open the hand. [1913 Webster] 3. To disclose; to reveal; to interpret; to explain. [1913 Webster] The king opened himself to some of his council, that he was sorry for the earl's death. --Bacon. [1913 Webster] Unto thee have I opened my cause. --Jer. xx. 12. [1913 Webster] While he opened to us the Scriptures. --Luke xxiv. 32. [1913 Webster] 4. To make known; to discover; also, to render available or accessible for settlements, trade, etc. [1913 Webster] The English did adventure far for to open the North parts of America. --Abp. Abbot. [1913 Webster] 5. To enter upon; to begin; as, to open a discussion; to open fire upon an enemy; to open trade, or correspondence; to open an investigation; to open a case in court, or a meeting. [1913 Webster] 6. To loosen or make less compact; as, to open matted cotton by separating the fibers. [1913 Webster] To open one's mouth, to speak. To open up, to lay open; to discover; to disclose. [1913 Webster] Poetry that had opened up so many delightful views into the character and condition of our "bold peasantry, their country's pride." --Prof. Wilson. [1913 Webster]
The Collaborative International Dictionary of English v.0.48:

Open \O"pen\, v. i. 1. To unclose; to form a hole, breach, or gap; to be unclosed; to be parted. [1913 Webster] The earth opened and swallowed up Dathan, and covered the company of Abiram. --Ps. cvi. 17. [1913 Webster] 2. To expand; to spread out; to be disclosed; as, the harbor opened to our view. [1913 Webster] 3. To begin; to commence; as, the stock opened at par; the battery opened upon the enemy. [1913 Webster] 4. (Sporting) To bark on scent or view of the game. [1913 Webster]
The Collaborative International Dictionary of English v.0.48:

Audience \Au"di*ence\, n. [F. audience, L. audientia, fr. audire to hear. See Audible, a.] 1. The act of hearing; attention to sounds. [1913 Webster] Thou, therefore, give due audience, and attend. --Milton. [1913 Webster] 2. Admittance to a hearing; a formal interview, esp. with a sovereign or the head of a government, for conference or the transaction of business. [1913 Webster] According to the fair play of the world, Let me have audience: I am sent to speak. --Shak. [1913 Webster] 3. An auditory; an assembly of hearers. Also applied by authors to their readers. [1913 Webster] Fit audience find, though few. --Milton. [1913 Webster] He drew his audience upward to the sky. --Dryden. [1913 Webster] Court of audience, or Audience court (Eng.), a court long since disused, belonging to the Archbishop of Canterbury; also, one belonging to the Archbishop of York. --Mozley & W. In general (or open) audience, publicly. To give audience, to listen; to admit to an interview. [1913 Webster]
WordNet (r) 3.0 (2006):

open adj 1: affording unobstructed entrance and exit; not shut or closed; "an open door"; "they left the door open" [syn: open, unfastened] [ant: closed, shut, unopen] 2: affording free passage or access; "open drains"; "the road is open to traffic"; "open ranks" [ant: closed] 3: with no protection or shield; "the exposed northeast frontier"; "open to the weather"; "an open wound" [syn: exposed, open] 4: open to or in view of all; "an open protest"; "an open letter to the editor" 5: used of mouth or eyes; "keep your eyes open"; "his mouth slightly opened" [syn: open, opened] [ant: closed, shut] 6: not having been filled; "the job is still open" 7: accessible to all; "open season"; "an open economy" 8: not defended or capable of being defended; "an open city"; "open to attack" [syn: assailable, undefendable, undefended, open] 9: (of textures) full of small openings or gaps; "an open texture"; "a loose weave" [syn: loose, open] 10: having no protecting cover or enclosure; "an open boat"; "an open fire"; "open sports cars" 11: (set theory) of an interval that contains neither of its endpoints [ant: closed] 12: not brought to a conclusion; subject to further thought; "an open question"; "our position on this bill is still undecided"; "our lawsuit is still undetermined" [syn: open, undecided, undetermined, unresolved] 13: not sealed or having been unsealed; "the letter was already open"; "the opened package lay on the table" [syn: open, opened] 14: without undue constriction as from e.g. tenseness or inhibition; "the clarity and resonance of an open tone"; "her natural and open response" 15: ready or willing to receive favorably; "receptive to the proposals" [syn: receptive, open] [ant: unreceptive] 16: open and observable; not secret or hidden; "an overt lie"; "overt hostility"; "overt intelligence gathering"; "open ballots" [syn: overt, open] [ant: covert] 17: not requiring union membership; "an open shop employs nonunion workers" 18: possibly accepting or permitting; "a passage capable of misinterpretation"; "open to interpretation"; "an issue open to question"; "the time is fixed by the director and players and therefore subject to much variation" [syn: capable, open, subject] 19: affording free passage or view; "a clear view"; "a clear path to victory"; "open waters"; "the open countryside" [syn: clear, open] 20: openly straightforward and direct without reserve or secretiveness; "his candid eyes"; "an open and trusting nature"; "a heart-to-heart talk" [syn: candid, open, heart-to-heart] 21: ready for business; "the stores are open" n 1: a clear or unobstructed space or expanse of land or water; "finally broke out of the forest into the open" [syn: open, clear] 2: where the air is unconfined; "he wanted to get outdoors a little"; "the concert was held in the open air"; "camping in the open" [syn: outdoors, out-of-doors, open air, open] 3: a tournament in which both professionals and amateurs may play 4: information that has become public; "all the reports were out in the open"; "the facts had been brought to the surface" [syn: open, surface] v 1: cause to open or to become open; "Mary opened the car door" [syn: open, open up] [ant: close, shut] 2: start to operate or function or cause to start operating or functioning; "open a business" [syn: open, open up] [ant: close, close down, close up, fold, shut down] 3: become open; "The door opened" [syn: open, open up] [ant: close, shut] 4: begin or set in action, of meetings, speeches, recitals, etc.; "He opened the meeting with a long speech" [ant: close] 5: spread out or open from a closed or folded state; "open the map"; "spread your arms" [syn: unfold, spread, spread out, open] [ant: fold, fold up, turn up] 6: make available; "This opens up new possibilities" [syn: open, open up] 7: become available; "an opportunity opened up" [syn: open, open up] 8: have an opening or passage or outlet; "The bedrooms open into the hall" 9: make the opening move; "Kasparov opened with a standard opening" 10: afford access to; "the door opens to the patio"; "The French doors give onto a terrace" [syn: afford, open, give] 11: display the contents of a file or start an application as on a computer [ant: close]
Moby Thesaurus II by Grady Ward, 1.0:

750 Moby Thesaurus words for "open": Spartan, abandoned, aboveboard, absolute, accented, acceptable, accessible, activate, admissible, admissive, admissory, adumbrate, advertise, affirmed, afford, agape, agreeable, air, ajar, aloof, altruistic, alveolar, ambiguous, amenable, amiable, announce, announced, apical, apico-alveolar, apico-dental, apparent, approachable, appropriate, arguable, articulated, artless, ascetic, assimilated, at issue, attainable, austere, authentic, available, back, bald, bare, barytone, be a gas, be a hit, begin, beholdable, beneficent, bighearted, bilabial, bill, billow, blatant, bluff, blunt, bomb, bona fide, born yesterday, bounteous, bountiful, branch, branch out, brazen, breach, break, break the seal, bring out, bring to light, broach, broad, broadcast, broken, brought to notice, brusque, cacuminal, campestral, campestrian, candid, central, cerebral, champaign, charitable, check, checked, childlike, chink, circulated, clear, cleared, cleave, close, come-at-able, commence, common, common knowledge, common property, commonplace, communicate, communicative, conditional, conditioned, confiding, consonant, consonantal, conspicuous, contingent, continuant, contribute, conversable, cordial, cover, crack, crevasse, current, cut, cut apart, cut open, debatable, declared, dehiscent, deltoid, demonstrative, dental, denuded, dependent, depending, deploy, deserted, detached, detectable, develop, diffused, dilate, direct, discernible, disclose, disclosed, disconnected, discontinuous, discover, discrete, dismask, dispart, disperse, display, disposed, disrupt, disseminated, dissimilated, distend, distributed, ditch, divaricate, divide, divulge, dorsal, downright, dramatize, draw the veil, dry, dubious, dubitable, dull, effusive, embark, employable, equivocal, establish, evident, exhibit, expand, expansive, explain, explicit, expose, exposed, exposed to view, extend, extended, extensive, extroverted, fail, fair, fair and square, fan, fan out, fan-shape, fan-shaped, fanlike, fanned, fanning, feature, findable, fissure, fit, flabelliform, flagrant, flare, flared, flaring, flat, flexible, flop, fly open, forsaken, forthright, foursquare, fracture, frank, frankhearted, free, free hand, free-acting, free-going, free-moving, free-speaking, free-spoken, free-tongued, freehanded, freehearted, friendly, front, full, furnish, furrow, gap, gaping, gapped, gash, generous, genial, genuine, get, get going, get under way, getatable, gettable, giving, glaring, glide, glossal, glottal, godforsaken, good-faith, gossipy, gracious, greathearted, groove, guileless, guttural, handsome, hanging out, hard, headline, heart-to-heart, hearty, heavy, high, hint, hole, homely, homespun, honest, hospitable, humanitarian, idle, illimitable, imbibitory, impart, impressionable, in circulation, in evidence, in full view, in plain sight, in print, in question, in suspense, in the balance, in view, inaugurate, incise, inclined, incoherent, inconsistent, indecisive, influenceable, ingenu, ingenuous, ingestive, initiate, innocent, insight, intonated, introduce, intromissive, intromittent, invitatory, inviting, kick off, labial, labiodental, labiovelar, large, largehearted, lateral, launch, lavish, lax, lay bare, lay open, lean, leisure, leisured, let daylight in, let out, liable, liberal, light, limitless, lingual, liquid, low, made public, magnanimous, make a hit, make known, make plain, malleable, manifest, mantle, matter-of-fact, melodramatize, mid, monophthongal, moot, mount, movable, munificent, muted, naive, naked, narrow, nasal, nasalized, natural, navigable, neat, neighborly, newsy, no strings, nonadherent, nonadhesive, noncoherent, noncohesive, nonimmune, noticeable, obnoxious, observable, obtainable, obvious, occlusive, offer, on the level, on the square, on the up-and-up, ope, open a show, open air, open and aboveboard, open as day, open fire, open to, open to all, open to view, open up, open-handed, open-minded, openhanded, openhearted, operative, out-of-doors, outcropping, outdoors, outgoing, outland, outside, outspoken, outspread, outstretch, outstretched, overgrow, overrun, overspread, overt, oxytone, palatal, palatalized, palpable, part, passable, patent, patulous, peeled, pendent, pending, penetrable, perceivable, perceptible, perfect, perforate, persuadable, persuasible, pervious, pharyngeal, pharyngealized, phonemic, phonetic, phonic, pierce, pitch, pitched, plain, plain-speaking, plain-spoken, plastic, pleasing, plenary, pliable, pliant, posttonic, practicable, predisposed, premiere, present, preview, princely, problematic, proclaimed, procurable, produce, profuse, prone, propagated, proper, prosaic, prosing, provide, public, publish, published, pull out, pure, put on, raise, raise the curtain, ramify, reachable, receivable, receptible, receptive, recipient, recognizable, release, rent, reported, responsive, retired, retroflex, reveal, revealed, rift, ringent, rip, rive, roomy, round, rounded, rupture, rustic, scenarize, securable, seeable, self-revealing, self-revelatory, semiretired, semivowel, sensitive, separate, set in motion, set the stage, set up, severe, shadow, show, show forth, show up, showing, simple, simple-speaking, simplehearted, simpleminded, sincere, single-hearted, single-minded, sit, slash, slit, slot, sober, sociable, soft, sonant, spacious, spare, splay, splayed, splaying, split, spraddle, spraddled, spraddling, sprangle, sprangled, sprangling, sprawl, sprawling, sprawly, spread, spread like wildfire, spread out, spreading, spring open, square, square-dealing, square-shooting, stage, star, stark, start, stated, stintless, stopped, straight, straight-out, straight-shooting, straightforward, stressed, stretch out, stretched-out, strip bare, stripped, strong, suasible, subject, succeed, suggest, suggestible, suitable, surd, susceptible, suspenseful, swayable, swell, swing open, syllabic, talkative, tap, tear, tear open, telecast, televised, tenantless, tense, tenuous, the open, the out-of-doors, theatricalize, thick, throaty, throw open, to be had, to be seen, tonal, tonic, transparent, trench, trustful, trusting, try out, twangy, unaccented, unadhesive, unadorned, unaffected, unbar, unbarred, unblock, unblocked, unbolt, unbolted, unbooked, unbound, unbounded, uncertain, unchecked, uncircumscribed, unclassified, uncloak, unclog, unclogged, unclosed, unclothe, unclouded, uncluttered, uncoherent, uncohesive, uncommitted, unconcealed, unconditional, unconditioned, unconfined, unconnected, unconstrained, uncork, uncounted, uncover, uncovered, undecided, undefended, undetermined, undisguised, undissembled, undissembling, undo, undrape, unencumbered, unequivocal, unestablished, unfasten, unfastened, unfilled, unfixed, unfold, unfolded, unfortified, unfurl, ungrudging, unguarded, unhampered, unhidden, unhindered, unimaginative, unimpeded, uninhabited, uninhibited, unjoined, unkennel, unlatch, unlimited, unlock, unlocked, unmanned, unmask, unmeasured, unobstructed, unoccupied, unpack, unpeopled, unpopulated, unprotected, unqualified, unrepressed, unreserved, unresolved, unrestrained, unrestricted, unreticent, unroll, unrounded, unscheduled, unscreen, unseal, unsealed, unsecretive, unselfish, unsettled, unsheathe, unsheltered, unshrinking, unshroud, unshut, unsigned, unsilent, unsophisticated, unsparing, unstaffed, unstinted, unstinting, unstop, unstopped, unstressed, unsuppressed, unsuspicious, untaken, untenacious, untenanted, untended, untie, untold, unvarnished, unveil, unwary, unwrap, up for grabs, up-and-up, usable, vacant, velar, veritable, viewable, visible, visual, vocalic, vocoid, voiced, voiceless, vowel, vowellike, warm, warmhearted, weak, welcoming, well-known, wide, wide open, wide-open, widely known, widen, widespread, willing, within reach, without, without strings, witnessable, yawning, yield
V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

OPEN [You-R] OPerating ENvironment (Infineon, RFID)
V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

OPEN Open Protocol Enhanced Networks
The Jargon File (version 4.4.7, 29 Dec 2003):

open n. Abbreviation for ?open (or left) parenthesis? ? used when necessary to eliminate oral ambiguity. To read aloud the LISP form (DEFUN FOO (X) (PLUS X 1)) one might say: ?Open defun foo, open eks close, open, plus eks one, close close.?
The Free On-line Dictionary of Computing (30 December 2018):

open 1. To prepare to read or write a file. This usually involves checking whether the file already exists and that the user has the necessary authorisation to read or write it. The result of a successful open is usually some kind of capability (e.g. a Unix file descriptor) - a token that the user passes back to the system in order to access the file without further checks and finally to close the file. 2. Abbreviation for "open (or left) parenthesis" - used when necessary to eliminate oral ambiguity. To read aloud the LISP form (DEFUN FOO (X) (PLUS X 1)) one might say: "Open defun foo, open eks close, open, plus eks one, close close." 3. Non-proprietary. An open standard is one which can be used without payment. 4. open interval.