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adjective, \ˈō-pən, -pəm\

Definition of open

opener play \ˈōp-nər, ˈō-pə-\ openest play \ˈōp-nəst, ˈō-pə-\

  1. 1 :  having no enclosing or confining barrier :  accessible on all or nearly all sides <cattle grazing on an open range>

  2. 2 a (1) :  being in a position or adjustment to permit passage :  not shut or locked <an open door> (2) :  having a barrier (as a door) so adjusted as to allow passage <the house was open> b :  having the lips parted <stood there with his mouth wide open> c :  not buttoned or zipped <an open shirt>

  3. 3 a :  completely free from concealment :  exposed to general view or knowledge <their hostilities eventually erupted with open war> b :  exposed or vulnerable to attack or question :  subject <open to doubt> c :  being an operation or surgical procedure in which an incision is made such that the tissues are fully exposed

  4. 4 a :  not covered with a top, roof, or lid <an open car> <her eyes were open> b :  having no protective covering <open wiring> <an open wound>

  5. 5 :  not restricted to a particular group or category of participants <open to the public> <open housing>: as a :  enterable by both amateur and professional contestants <an open tournament> b :  enterable by a registered voter regardless of political affiliation <an open primary>

  6. 6 :  fit to be traveled over :  presenting no obstacle to passage or view <the open road> <open country>

  7. 7 :  having the parts or surfaces laid out in an expanded position :  spread out :  unfolded <an open book>

  8. 8 a (1) :  low 13 (2) :  formed with the tongue in a lower position <Italian has an open and a close e> b (1) :  having clarity and resonance unimpaired by undue tension or constriction of the throat <an open vocal tone> (2) of a tone :  produced by an open string or on a wind instrument by the lip without the use of slides, valves, or keys

  9. 9 a :  available to follow or make use of <the only course open to us> b :  not taken up with duties or engagements <keep an hour open on Friday> c :  not finally decided :  subject to further consideration <the salary is open> <an open question> d :  available for a qualified applicant :  vacant <the job is still open> e :  remaining available for use or filling until canceled <an open order for more items> f :  available for future purchase <these items are in open stock> g :  available for breeding :  not now pregnant <an open heifer> h :  not proprietary :  available to third party developers <open source code>

  10. 10 a :  characterized by ready accessibility and usually generous attitude: as (1) :  generous in giving (2) :  willing to hear and consider or to accept and deal with :  responsive (3) :  free from reserve or pretense :  frank b :  accessible to the influx of new factors (as foreign goods) <an open market>

  11. 11 a :  having openings, interruptions, or spaces <open mesh>: as (1) :  being porous and friable <open soil> (2) :  sparsely distributed :  scattered <open population> (3) of a compound :  having components separated by a space in writing or printing (as opaque projector) b :  not made up of a continuous closed circuit of channels <the insect circulatory system is open>

  12. 12 a of an organ pipe :  not stopped at the top b of a string on a musical instrument :  not stopped by the finger

  13. 13 :  being in operation <an open microphone>; especially :  ready for business, patronage, or use <the store is open from 9 to 5> <the new highway will be open next week>

  14. 14 a (1) :  characterized by lack of effective regulation of various commercial enterprises <an open town> (2) :  not repressed by legal controls <open gambling> b :  free from checking or hampering restraints <an open economy> c :  relatively unguarded by opponents <passed to an open teammate>

  15. 15 :  having been opened by a first ante, bet, or bid <the bidding is open>

  16. 16 of punctuation :  characterized by sparing use especially of the comma

  17. 17 a :  containing none of its endpoints <an open interval> b :  being a set or composed of sets each point of which has a neighborhood all of whose points are contained in the set <the interior of a sphere is an open set>

  18. 18 a :  being an incomplete electrical circuit b :  not allowing the flow of electricity <an open switch>

  19. 19 of a universe :  having insufficient mass to halt expansion gravitationally

open adverb
openly play \ˈō-pən-lē\ adverb
openness play \-pə(n)-nəs\ noun

Examples of open in a sentence

  1. The door suddenly swung open.

  2. You left the blinds wide open.

  3. The meat was roasted over an open fire.

  4. I was so tired that I couldn't keep my eyes open.

  5. Don't chew with your mouth open.

  6. staring with her eyes wide open

  7. There's already an open jar of pickles in the refrigerator.

  8. They kept the road open throughout the winter.

Origin of open

Middle English, from Old English; akin to Old High German offan open, Old English ūp up

First Known Use: before 12th century

Synonym Discussion of open

frank, candid, open, plain mean showing willingness to tell what one feels or thinks. frank stresses lack of shyness or secretiveness or of evasiveness from considerations of tact or expedience <frank discussions>. candid suggests expression marked by sincerity and honesty especially in offering unwelcome criticism or opinion <a candid appraisal>. open implies frankness but suggests more indiscretion than frank and less earnestness than candid <open in saying what they think>. plain suggests outspokenness and freedom from affectation or subtlety in expression <plain talk>.

liable, open, exposed, subject, prone, susceptible, sensitive mean being by nature or through circumstances likely to experience something adverse. liable implies a possibility or probability of incurring something because of position, nature, or particular situation <liable to get lost>. open stresses a lack of barriers preventing incurrence <a claim open to question>. exposed suggests lack of protection or powers of resistance against something actually present or threatening <exposed to infection>. subject implies an openness for any reason to something that must be suffered or undergone <all reports are subject to review>. prone stresses natural tendency or propensity to incur something <prone to delay>. susceptible implies conditions existing in one's nature or individual constitution that make incurrence probable <very susceptible to flattery>. sensitive implies a readiness to respond to or be influenced by forces or stimuli <unduly sensitive to criticism>.

Both liable and apt when followed by an infinitive are used nearly interchangeably with likely. Although conflicting advice has been given over the years, most current commentators accept apt when so used. They generally recommend limiting liable to situations having an undesirable outcome, and our evidence shows that in edited writing it is more often so used than not.




Simple Definition of open

  • : to move (a door, window, etc.) so that an opening is no longer covered

  • : to move and no longer cover an opening

  • : to cause (something) to no longer be covered, sealed, or blocked

Source: Merriam-Webster's Learner's Dictionary

Full Definition of open

opened play \ˈō-pənd, ˈō-pəmd\ opening play \ˈōp-niŋ, ˈō-pə-\

  1. transitive verb
  2. 1 a :  to move (as a door) from a closed position b :  to make available for entry or passage by turning back (as a barrier) or removing (as a cover or an obstruction)

  3. 2 a :  to make available for or active in a regular function <open a new store> b :  to make accessible for a particular purpose <opened new land for settlement> c :  to initiate access to (a computer file) prior to use

  4. 3 a :  to disclose or expose to view :  reveal b :  to make more discerning or responsive :  enlighten <must open our minds to the problems> c :  to bring into view or come in sight of by changing position

  5. 4 a :  to make an opening in <opened the boil> b :  to loosen and make less compact <open the soil>

  6. 5 :  to spread out :  unfold <opened the book>

  7. 6 a :  to enter upon :  begin <opened the meeting> b :  to commence action in a card game by making (a first bid), putting a first bet in (the pot), or playing (a card or suit) as first lead

  8. 7 :  to restore or recall (as an order) from a finally determined state to a state in which the parties are free to prosecute or oppose

  9. intransitive verb
  10. 1 :  to become open <the office opened early>

  11. 2 a :  to spread out :  expand <the wound opened under the strain> b :  to become disclosed <a beautiful vista opened before us>

  12. 3 :  to become enlightened or responsive

  13. 4 :  to give access <the rooms open onto a hall>

  14. 5 :  speak out 2 <finally he opened freely on the subject>

  15. 6 a :  to begin a course or activity b :  to make a bet, bid, or lead in commencing a round or hand of a card game

  16. 7 :  to provide the opening performance of a show before the main event

openability play \ˌōp-nə-ˈbi-lə-tē, ˌō-pə-\ noun
openable play \ˈōp-nə-bəl, ˈō-pə-\ adjective

Examples of open in a sentence

  1. This door is hard to open.

  2. Open the door! shouted the police officer.

  3. Would you mind if I opened a window?

  4. The car door opened and a beautiful woman stepped out.

  5. The door opened and closed so quietly that I didn't notice he had come in the room.

  6. This drawer is stuck. It just won't open!

  7. She comes home, turns on the TV, and starts opening her mail.

  8. She opened her eyes and smiled at me.

  9. I opened my umbrella and stepped out into the rain.

  10. Open your mouth wide for me, said the dentist.

Before 12th Century

First Known Use of open

before 12th century




Simple Definition of open

  • : a competition (such as a major golf tournament or tennis tournament) that allows both professionals and amateurs to participate

  • the open : an area or place without walls, barriers, etc. : an area or place that is not covered or enclosed

  • : a situation in which something (such as a feeling) is no longer hidden or kept secret

Source: Merriam-Webster's Learner's Dictionary

Full Definition of open

  1. 1 :  opening

  2. 2 :  open and unobstructed space: as a :  open air b :  open water

  3. 3 :  an open contest, competition, or tournament

  4. 4 :  a public or unconcealed state or position

Examples of open in a sentence

  1. <a daguerreotype of a cowboy whose face is roughened from a hard life in the open>

13th Century

First Known Use of open

13th century

OPEN Defined for Kids



adjective \ˈō-pən\

Definition of open for Students

  1. 1 :  not shut or blocked :  not closed <an open window> <open books>

  2. 2 :  not sealed, locked, or fastened <an open zipper> <There's an open bottle of ketchup in the refrigerator.>

  3. 3 :  easy to enter, get through, or see <open country>

  4. 4 :  ready to consider appeals or ideas <an open mind>

  5. 5 :  not drawn together :  spread out <an open flower> <open umbrellas>

  6. 6 :  not enclosed or covered <an open boat> <an open fire>

  7. 7 :  not secret :  public <They have an open dislike for one another.>

  8. 8 :  to be used, entered, or taken part in by all <an open meeting> <It was an open race—any number of dogs could be entered. — John Reynolds Gardiner, Stone Fox>

  9. 9 :  not decided or settled <an open question>

openly adverb
openness noun




Definition of open for Students


  1. 1 :  to change or move from a shut condition <Sit down and open a book.> <The door opened.> <She opened her eyes.>

  2. 2 :  to clear by or as if by removing something in the way <Workers were sent to open a road blocked with snow.>

  3. 3 :  to make or become ready for use <They plan to open a store.> <The office opens at eight.>

  4. 4 :  to give access <The rooms open onto a hall.>

  5. 5 :  begin 1, start <Police have opened an investigation.> <They opened fire on the enemy.>

opener \ˈō-pə-nər, ˈōp-nər\ noun




Definition of open for Students

  1. :  space that is not enclosed or covered :  outdoors <Some slept in a cabin while others slept in the open.>

Medical Dictionary



adjective \ˈō-pən\

Medical Definition of open

  1. 1a:  not covered, enclosed, or scabbed over <an open lesion> <an open running ulcer>b:  not involving or encouraging a covering (as by bandages or overgrowth of tissue) or enclosure <open treatment of burns>c:  relating to or being a compound fractured:  being an operation or surgical procedure in which an incision is made such that the tissues and organs are fully exposed—compare open-heart

  2. 2:  shedding the infective agent to the exterior <open tuberculosis>—compare closed 3

  3. 3a:  unobstructed by congestion or occlusion <open sinuses>b:  not constipated <open bowels>

  4. 4:  using a minimum of physical restrictions and custodial restraints on the freedom of movement of the patients or inmates <an open psychiatric ward>




Medical Definition of open

opened; opening

  1. 1

  2. transitive verb

  3. a:  to make available for entry or passage by removing (as a cover) or clearing away (as an obstruction)b:  to free (a body passage) of congestion or occlusion <an inhalator for opening congested nasal passages> <open clogged arteries>

  4. 2:  to make one or more openings in <opened the boil>

  5. intransitive verb

  6. :  to spread out <the wound opened>

Law Dictionary




Legal Definition of open

  1. 1 :  exposed to general view or knowledge :  free from concealment <an open, notorious, continuous, and adverse use of the property> <an open and obvious danger> Editor's note: When a defect, hazard, or condition is open such that a reasonable person under the circumstances should have recognized the danger posed by it, a defendant is usually relieved of liability for failure to warn.

  2. 2 :  not restricted to a particular group or category of participants; specifically :  enterable by a registered voter regardless of political affiliation <an open primary>

  3. 3a :  being in effect or operation <an open mine> <a bench warrant still open> b :  available for use <an open toll road> c :  not finally determined, decided, or settled :  subject to further consideration <an open question> d :  remaining effective or available for use until canceled <an open insurance contract>

  4. 4 :  not repressed or regulated by legal controls <a state with open gambling>




Legal Definition of open


  1. transitive verb
  2. 1 :  to begin the process of <open the succession>

  3. 2a :  to make the statement by which the trial of (a case) is begun and put before the court b :  to be the first to speak in summing up or arguing (a case)

  4. 3 :  to restore or recall (as an order, rule, or judgment) from a finally determined state to a state in which the parties are free to prosecute or oppose by further proceedings

  5. intransitive verb
  6. 1 :  to begin action :  commence on some course or activity <the stock opened at par>

  7. 2 :  to begin the trial of a case <defendant…has the option of presenting an opening statement immediately after plaintiff opens — J. H. Friedenthal et al.>

Seen and Heard

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to dishevel or rumple

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