Synonyms

open

American

[oh-puhn] / ˈoʊ pən /

adjective

not closed or barred at the time, as a doorway by a door, a window by a sash, or a gateway by a gate.

to leave the windows open at night.
(of a door, gate, window sash, or the like) set so as to permit passage through the opening it can be used to close.
having no means of closing or barring.

an open portico.
having the interior immediately accessible, as a box with the lid raised or a drawer that is pulled out.
relatively free of obstructions to sight, movement, or internal arrangement.

an open floor plan.
constructed so as to be without cover or enclosure on the top or on some or all sides.

an open boat.
having relatively large or numerous spaces, voids, or intervals.

an open architectural screen; open ranks of soldiers.
perforated or porous.

an open texture.
relatively unoccupied by buildings, fences, trees, etc..

open country.
not covered or closed; with certain parts apart.

open eyes; open mouth.
without a covering, especially a protective covering; unprotected; unenclosed; exposed.

an open wound; open electrical wires.
extended or unfolded.

an open newspaper.
without restrictions as to who may participate.

an open competition; an open session.
accessible or available to follow.

the only course still open to us.
not taken or filled; not preempted; available; vacant.

Which job is open?
ready for or carrying on normal trade or business.

The new store is now open. The office is open on Saturdays.
not engaged or committed.

Have you any open time on Monday?
accessible, as to appeals, ideas, or offers.

to be open to suggestion.
exposed to general view or knowledge; existing, carried on, etc., without concealment.

open disregard of the rules.
acting publicly or without concealment, as a person.
unreserved, candid, or frank, as persons or their speech, aspect, etc..

an open manner.
generous, liberal, or bounteous.

to give with an open hand.
liable or subject.

open to question; open to retaliation.
undecided; unsettled.

several open questions.
without effective or enforced legal, commercial, or moral regulations.

an open town.
unguarded by an opponent.

an open wide receiver.
noting the part of the sea beyond headlands or enclosing areas of land.

to sail on the open seas.
free of ice, as a body of water or a seaport.
free of navigational hazards.

an open coast.
(of a seaport) available for foreign trade; not closed by government regulations or by considerations of health.
(of a microphone) in operation; live.
(of a delimiting punctuation mark) occurring at the beginning of a group of words or characters that is set off, as from surrounding text.

open parenthesis; open quotes.
not yet balanced or adjusted, as an account.
not constipated, as the bowels.
Phonetics.
1. (of a vowel) articulated with a relatively large opening above the tongue or with a relatively large oral aperture, as the vowel sound of cot compared with that in caught.
2. (of a syllable) ending with a vowel.
3. (of a consonant) continuant (opposed to stop).
Linguistics. (of a class of items) readily admitting new members, as the class of nouns, verbs, or adjectives (opposed to closed).
Printing.
1. (of type) in outline form.
2. widely spaced or leaded, as printed matter.
Music.
1. (of an organ pipe) not closed at the far end.
2. (of a string) not stopped by a finger.
3. (of a note) produced by such a pipe or string or, on a wind instrument, without the aid of a slide, key, etc.
Mathematics.
1. (of an interval) containing neither endpoint.
2. (of a set) consisting of points having neighborhoods wholly contained in the set, as the set of points within a circle.
3. (of a map from one topological space to another) having the property that the image of an open set is an open set.
free from frost; mild or moderate.

an open winter.
Animal Husbandry. (of a female animal) not pregnant.
Textiles. (of a fabric or weave) so loosely woven that spaces are visible between warp and filling yarns.

verb (used with object)

to move (a door, window sash, etc.) from a shut or closed position so as to admit of passage.
to render (a doorway, gateway, window, etc.) unobstructed by moving a door, window sash, etc., away from it.
to render the interior of (a box, drawer, etc.) readily accessible.
to clear (a passage, channel, etc.) of obstructions.
to clear (areas or passages in the body).
to give access to; make accessible or available, as for use.

to open a port for trade.
to establish for business purposes or for public use.

to open an office.
to set in action, begin, start, or commence (sometimes followed byup ).

to open a campaign.
to uncover, lay bare, or expose to view.
to expand, unfold, or spread out.

to open a map.
to make less compact, less closely spaced, or the like.

to open ranks.
to disclose, reveal, or divulge.
to render accessible to knowledge, enlightenment, sympathy, etc..

to open one's mind.
to cut, blast, or break into.

to open a safe with nitro.
to make or produce (an opening) by cutting or breaking, or by pushing aside or removing obstructions.

to open a way through a crowd.
to make an incision or opening in.

to open a boil.
Law.
1. to recall or revoke (a judgment, decree, etc.) for the purpose of allowing further contest or delay.
2. to make the first statement of (a case) to the court or jury.
Cards. to begin a hand by making (the first bid), placing (the first bet), or playing (a given card or suit) as the lead.
Nautical. to sail (a course) so that the apparent location of a distant fixed object changes with relation to a nearer fixed object (sometimes followed byout ).

verb (used without object)

to become open, as a door, building, box, or enclosure.
to afford access.

a door that opens into a garden.
to have an opening, passage, or outlet.

The room opens into a corridor.
(of a building, theater, etc.) to open its doors to the public.

The museum opens at one o'clock.
to begin a session or term, as a school.
to begin a season, series of performances, or tour, as a theatrical company.

The play will open in Boston.
to begin, start, or commence an activity.

The game opened with the national anthem.
to part, or seem to part, so as to allow or reveal a passage.

At last the cliffs opened to show us that we were heading for the sea.
to become disclosed or revealed.
to come into view; become more visible or plain.
to become receptive to knowledge, sympathy, etc., as the mind.
to disclose or reveal one's knowledge, thoughts, feelings, etc.
to unfold or expand, as a blossom, so as to reveal the interior.
to spread out or expand, as the hand or a fan.
to spread apart or separate, as pages of a book, newspaper, etc..

Open to page 32.
to spread or come apart; burst.

The wound opened.
to become less compact, less closely spaced, or the like.

The ranks began to open.
Cards. to make the first bet, bid, or lead in beginning a hand.
Hunting. (of hounds) to begin to bark, as on the scent of game.

noun

an open or clear space.
the open air.
the open water, as of the sea.
an opening or aperture.
an opening or opportunity.
a contest or tournament in which both amateurs and professionals may compete, especially in golf and tennis.
the open,
1. the unenclosed or unobstructed country.
2. the outdoors.
  
  Vacations in the open are fine for the entire family.
3. the condition of being unconcealed, recognized, or publicly known.
  
  The scandal is now out in the open.

verb phrase

open up
1. to become or make open.
2. to expand, especially before the eye.
  
  A breathtaking panorama opened up as we reached the top of the hill.
3. to achieve the initial development of.
  
  to open up a business office; to open up trade with China.
4. Slang. to increase speed or the speed of (a vehicle).

open British

/ ˈəʊpən /

adjective

not closed or barred

the door is open
affording free passage, access, view, etc; not blocked or obstructed

the road is open for traffic
not sealed, fastened, or wrapped

an open package
having the interior part accessible

an open drawer
extended, expanded, or unfolded

an open newspaper
an open flower
ready for business

the shops are open
able to be obtained; available

the position advertised last week is no longer open
unobstructed by buildings, trees, etc

open countryside
free to all to join, enter, use, visit, etc

an open competition
unengaged or unoccupied

the doctor has an hour open for you to call
See open season
not decided or finalized

an open question
ready to entertain new ideas; not biased or prejudiced

an open mind
unreserved or candid

she was very open in her description
liberal or generous

an open hand
extended or eager to receive (esp in the phrase with open arms )
exposed to view; blatant

open disregard of the law
liable or susceptible

you will leave yourself open to attack if you speak
(of climate or seasons) free from frost; mild
free from navigational hazards, such as ice, sunken ships, etc

open water
without legal restrictions or enforceable regulations, esp in relation to gambling, vice, etc

an open town
without barriers to prevent absconding

an open prison
having large or numerous spacing or apertures

open ranks
full of small openings or gaps; porous

an open texture
printing (of type matter) generously leaded or widely spaced
music
1. (of a violin or guitar string) not stopped with the finger
2. (of a pipe, such as an organ pipe) not closed at either end
3. (of a note) played on such a string or pipe
commerce
1. in operation; active
  
  an open account
2. unrestricted; unlimited
  
  open credit
  open insurance cover
See open cheque
(of a return ticket) not specifying a date for travel
sport
1. (of a goal, court, etc) unguarded or relatively unprotected
  
  the forward missed an open goal
2. (of a stance, esp in golf) characterized by the front of the body being turned forward
(of a wound) exposed to the air
(esp of the large intestine) free from obstruction
undefended and of no military significance

an open city
phonetics
1. denoting a vowel pronounced with the lips relatively wide apart
2. denoting a syllable that does not end in a consonant, as in pa
chess (of a file) having no pawns on it
maths (of a set) containing points whose neighbourhood consists of other points of the same set

points inside a circle are an open set
computing (of software or a computer system) designed to an internationally agreed standard in order to allow communication between computers, irrespective of size, maufacturer, etc

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

verb

to move or cause to move from a closed or fastened position

to open a window
to render, be, or become accessible or unobstructed

to open a road
to open a parcel
the door opens into the hall
(intr) to come into or appear in view

the lake opened before us
(tr) to puncture (a boil) so as to permit drainage
to extend or unfold or cause to extend or unfold

to open a newspaper
to disclose or uncover or be disclosed or uncovered

to open one's heart
to cause (the mind) to become receptive or (of the mind) to become receptive
to operate or cause to operate

to open a shop
to make or become less compact or dense in structure

to open ranks
to set or be set in action; start

to open a discussion
to open the batting
(tr) to arrange for (a bank account, savings account, etc) usually by making an initial deposit
to turn to a specified point in (a book, magazine, etc)

open at page one
law to make the opening statement in (a case before a court of law)
(intr) cards to bet, bid, or lead first on a hand

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

noun

any wide or unobstructed space or expanse, esp of land or water
See open air
sport a competition which anyone may enter
to make evident or public
to become) evident or public

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

open Idioms

More idioms and phrases containing open

Synonym Usage

See frank ¹.

Other Word Forms

Derived Forms

Inflected Forms

Participles

Conjugated Forms

Present

Past

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Etymology

Origin of open

First recorded before 900; (adjective) Middle English, Old English; cognate with Old Saxon opan ( Dutch open ), Old High German offan ( German offen ), Old Norse opinn, akin to up; (verb) Middle English openen, Old English openian; cognate with Old Saxon opanon ( Dutch openen ), Old High German offanōn ( German öffnen )

Explanation

Something that's open allows you to move or see through it, like an open window or an open gate. The adjective open describes something that's not closed or blocked up, like open curtains that provide a view of the garden outside. Open can also refer to something that's unfastened or parted — an open jar of peanut butter, an open eye, or an open book. Things that are vulnerable, straightforward, or uncovered are also open, and if you are open to suggestions, it means you are willing to consider new ideas.

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

open opens opened opening

“I had to — it was either open for them or for Uriah Heep.”

From Los Angeles Times ● Aug. 10, 2026

The hot weather meant the risk of fires in the open remained high, and the fire service urged people to be mindful of behaviour that could start a blaze.

From BBC ● Aug. 10, 2026

Zuckerberg said in an Instagram video Monday that his company would open the weights for its latest AI model, enabling it to be downloaded by the public.

From Barron's ● Aug. 10, 2026

Tristan Jones KC, prosecuting, said Razzell, who is currently in an open prison, had been "compliant with conditions" and had engaged in 20 sessions with a psychologist.

From BBC ● Aug. 10, 2026

“That’s fine, young one. Stop on by whenever you want. The drive-in is open seven days a week, thirteen moon cycles a year. But there’s always a legendary grandparent or two around.”

From "Legendary Frybread Drive-In" by Cynthia Leitich Smith

Rapper Dave, who has numerous Brit Awards, Ivor Novellos and a Mercury Prize to his name, opens up Kamal's track, The People That Saved Me, with poignant lyrics about love and memories.

From BBC ● Aug. 10, 2026

"Learning to engineer these interfaces with atomic precision opens new opportunities for designing future semiconductor devices that would be difficult to achieve by changing individual materials alone."

From Science Daily ● Aug. 9, 2026

In a moment when no one can quite agree on how to properly address what’s so clearly happening before our eyes with Grande, a film like “Maddie’s Secret” opens a dialogue.

From Salon ● Aug. 8, 2026

“This extra week between the Kentucky Derby and the Preakness opens the Preakness to potential participants who use modern training methods.”

From The Wall Street Journal ● Aug. 8, 2026

The door slowly opens, and Jonah peeks in.

From "Keeping Pace" by Laurie Morrison

Coach Trevor Painter, aware it may be some time before Hodgkinson can move again, places an opened umbrella beside his star athlete to shield her from the incessant rain, before running for cover.

From BBC ● Aug. 10, 2026

As the Cold War waned and airlines expanded, travel opened up further to the masses.

From The Wall Street Journal ● Aug. 10, 2026

Roughly 600 cats have been adopted since Tail Town opened.

From Los Angeles Times ● Aug. 10, 2026

Thirsty Beijingers have another option: free AI for customers at AGI Bar, which opened last summer as a hub for developers, founders and investors.

From Barron's ● Aug. 10, 2026

He opened his jaws and let it dribble back into his teacup just as Gingersnipes turned around.

From "The Undead Fox of Deadwood Forest" by Aubrey Hartman

That will be especially important with last season's mainstays Azor Matusiwa and Jack Taylor doubtful for the opening game following operations over the summer.

From BBC ● Aug. 10, 2026

The album opens with one of the best opening tracks of any debut album: “Blitzkrieg Bop.”

From Salon ● Aug. 10, 2026

Destination Crenshaw broke ground in February 2020 and was supposed to have a public opening in February 2024, according to a 2023 architectural fact sheet.

From Los Angeles Times ● Aug. 10, 2026

The U.S. dollar found modest support during the Asian session, but uncertainty around the opening of the strait is keeping risk sentiment cautious, said Samara Hammoud, currency strategist at Commonwealth Bank of Australia.

From The Wall Street Journal ● Aug. 10, 2026

We spent the evening helping him through the opening quests and getting him equipped well enough to fight the local bears.

From "Bye Forever, I Guess" by Jodi Meadows

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

open

adjective

verb (used with object)

verb (used without object)

noun

verb phrase

adjective

verb

noun

More idioms and phrases containing open

Synonym Usage

Other Word Forms

Derived Forms

Inflected Forms

Participles

Conjugated Forms

Present

Past

Future

Etymology

Origin of open

Explanation

Example Sentences

See Examples For:

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