1
: having no enclosing or confining barrier : accessible on all or nearly all sides
cattle grazing on an open range
2
a(1)
: being in a position or adjustment to permit passage : not shut or locked
an open door
(2)
: having a barrier (such 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
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
a
: not covered with a top, roof, or lid
an open car
her eyes were open
b
: having no protective covering
open wiring
5
a
: having the skin cracked, cut, or broken so that underlying tissue is exposed
abrasions, lacerations, and other open wounds
see also open fracture
b
of a head injury
: marked by fracture or penetration of the skull
6
: not restricted to a particular group or category of participants
open to the public
open housing
: such as
a
: enterable by both amateur (see amateur sense 1) and professional (see professional entry 1 sense 2a) contestants
an open tournament
b
: enterable by a registered voter regardless of political affiliation
an open primary
7
a
: presenting no obstacle to passage or view : not enclosed, obstructed, or filled with objects
the open road
open country
see also open water
b
of large bodies of water
: away from the coastal regions : pelagic
fish of the open ocean
In open seas, the smaller the ship, the more motion you can expect.—
Matt Hannafin et al.
Matt Hannafin et al.8
: having the parts or surfaces laid out in an expanded position : spread out : unfolded
an open book
9
a(1)
: low sense 15
an open vowel
(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
10
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
computers
: not proprietary : available to third party developers
But while IBM pushes Notes, a proprietary technology created in the 1980s, a raft of new and much smaller rivals is plying the "open" technology of the 1990s: software on the World Wide Web, the fastest growing part of the Internet.—Bart Ziegler
compare open-source
Bart Ziegler11
a
: characterized by ready accessibility and usually generous attitude: such as
(1)
: generous in giving
(2)
: willing to hear and consider or to accept and deal with : responsive
open to an offer
open to suggestion
(3)
: free from reserve or pretense : frank
was open about his personal life
(4)
of a relationship
: not restricted to one partner at a time by mutual agreement see also open marriage
b
: accessible to the influx of new factors (such as foreign goods)
an open market
12
a
: having openings, interruptions, or spaces
open mesh
: such as
(1)
: being porous (see porous sense 2a) and friable
open soil
(2)
: sparsely distributed : scattered
open population
(3)
of a compound
: having components (see component entry 1 sense 1) separated by a space in writing or printing (such as opaque projector)
b
: not made up of a continuous closed circuit (see circuit entry 1 sense 2a) of channels
the insect circulatory system is open
13
a
of an organ pipe
: not stopped at the top
b
of a string on a musical instrument
: not stopped by the finger
14
: 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
15
a(1)
: characterized by lack of effective regulation of various commercial enterprises (see enterprise sense 2)
an open town
(2)
: not repressed (see repress sense 1) 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
16
: having been opened by a first ante, bet, or bid
the bidding is open
17
of punctuation
: characterized by sparing use especially of the comma when possible without causing misinterpretation
18
mathematics
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
19
a
: being an incomplete electrical circuit
b
: not allowing the flow of electricity
an open switch
20
of a universe
: having insufficient mass (see mass entry 2 sense 1c) to halt expansion gravitationally
1
a
: to move (something, such as a door) from a closed position
b
: to make available for entry or passage by turning back (something, such as a barrier) or removing (something, such as a cover or an obstruction)
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
3
4
a
: to make an opening in
opened the boil
b
: to loosen and make less compact
open the soil
5
: to spread out : unfold
opened the book
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
7
: to restore or recall (something, such as an order) from a finally determined state to a state in which the parties are free to prosecute or oppose
1
: to become open
the office opened early
2
a
: to spread out : expand
the wound opened under the strain
b
: to become disclosed
a beautiful vista opened before us
3
: to become enlightened or responsive
4
: to give access
the rooms open onto a hall
5
: speak out sense 2
finally he opened freely on the subject
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
7
: to provide the opening performance of a show before the main event
Examples of open in a Sentence
Adjective
The door suddenly swung open.
You left the blinds wide open.
The meat was roasted over an open fire.
I was so tired that I couldn't keep my eyes open.
Don't chew with your mouth open.
staring with her eyes wide open
There's already an open jar of pickles in the refrigerator.
They kept the road open throughout the winter.
Verb
This door is hard to open.
“Open the door!” shouted the police officer.
Would you mind if I opened a window?
The car door opened and a beautiful woman stepped out.
The door opened and closed so quietly that I didn't notice he had come in the room.
This drawer is stuck. It just won't open!
She comes home, turns on the TV, and starts opening her mail.
She opened her eyes and smiled at me.
I opened my umbrella and stepped out into the rain.
“Open your mouth wide for me,” said the dentist.
Noun
a daguerreotype of a cowboy whose face is roughened from a hard life in the open
Recent Examples on the Web
Literary Hub, 27 Oct. 2025
Robinson expects most businesses to be open by mid-year 2026.
—Andy Humbles, Nashville Tennessean, 27 Oct. 2025
Leo Bertucci, Louisville Courier Journal, 25 Oct. 2025
The Jays found themselves in a 2-0 hole heading into the bottom of the fourth inning, as the Dodgers looked well on their way to their fourth straight series-opening win this postseason.
—Jacob Lev, CNN Money, 25 Oct. 2025
Lars Brandle, Billboard, 27 Oct. 2025
Just hours before the thieves quietly stole the historic coins, four chainsaw-wielding thieves broke into the Louvre Museum in Paris using a ladder boosted by a mechanical boom truck to force a window open at the famed museum and steal millions of dollars worth of jewelry.
—Desiree Anello, PEOPLE, 25 Oct. 2025
See All Example Sentences for open
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Adjective
The coronal magnetic field is therefore constantly under immense strain, and when that strain becomes too great, its tangled magnetic field lines snap open.
—Literary Hub, 27 Oct. 2025
Robinson expects most businesses to be open by mid-year 2026.
—Andy Humbles, Nashville Tennessean, 27 Oct. 2025
Verb
The landmark interpretive center, which opened to the public in 1994, is a hub for education on the Devonian period.
—Leo Bertucci, Louisville Courier Journal, 25 Oct. 2025
The Jays found themselves in a 2-0 hole heading into the bottom of the fourth inning, as the Dodgers looked well on their way to their fourth straight series-opening win this postseason.
—Jacob Lev, CNN Money, 25 Oct. 2025
Noun
The film which had been on track for an open in the $10 million-$12 million range domestically and $20 million globally.
—Lars Brandle, Billboard, 27 Oct. 2025
Just hours before the thieves quietly stole the historic coins, four chainsaw-wielding thieves broke into the Louvre Museum in Paris using a ladder boosted by a mechanical boom truck to force a window open at the famed museum and steal millions of dollars worth of jewelry.
—Desiree Anello, PEOPLE, 25 Oct. 2025
See All Example Sentences for open
Cite this Entry
“Open.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/open. Accessed 31 Oct. 2025.
Copy CitationKids Definition
open
1 of 3 adjective
ˈō-pən 
ˈōp-ᵊm
1
: allowing passage : not shut or blocked
an open door
open books
open pores
2
: not enclosed or covered
an open boat
an open fire
open wounds
3
a
: not secret : public
open dislike
b
: liable sense 2
open to challenge
4
a
: free to be used, entered, or taken part in by all
an open meeting
an open golf tournament
b
: easy to enter, get through, or see
open country
5
: not drawn together : spread out
an open flower
an open umbrella
6
a
: available for use : free
keep an hour open tomorrow
the only option open to us
b
: not decided or settled
an open question
c
: waiting to be filled
the job is still open
d
: available for purchase all or most of the time
these items are in open stock
7
: ready to consider appeals or ideas
an open mind
open to suggestion
8
: not allowing the flow of electricity : being an incomplete electrical circuit
an open switch
open
2 of 3 verb
opened
ˈō-pənd
ˈōp-ᵊmd
; opening
ˈōp-(ə-)niŋ
1
a
: to change or move from a shut or closed condition
open a book
the door opened
b
: to clear by or as if by removing something in the way
open a road blocked with snow
the clouds opened
c
: to make an opening in
open a boil
2
a
: to make or become ready for use
open a new store
b
: to make available for a certain purpose
open land for settlement
opened Japan to foreign trade
the office opens at eight
c
: to access for use
open the computer file
3
: to have an opening
the rooms open onto a hall
4
: begin sense 1, start
opened fire
open talks
open
3 of 3 noun1
: open space
2
: a contest or tournament that is open
3
: a state or position that is public or is not concealed
Medical Definition
open
1 of 2 adjective1
a(1)
: having the skin cracked, cut, or broken so that underlying tissue is exposed
abrasions, lacerations, and other open wounds
see also open fracture
(2)
of a head injury
: marked by fracture or penetration of the skull
b
: not involving or encouraging a covering (as by bandages or overgrowth of tissue) or enclosure
open treatment of burns
c
: 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
: shedding the infectious agent to the exterior
open tuberculosis
compare closed sense 3
3
a
: unobstructed by congestion or occlusion
open sinuses
b
: not constipated
open bowels
4
: using a minimum of physical restrictions and custodial restraints on the freedom of movement of the patients or inmates
an open psychiatric ward
open
2 of 2 verb
opened; opening
1
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
2
: to make one or more openings in
opened the boil
: to spread out
the wound opened
Legal Definition
open
1 of 2 adjective1
: exposed to general view or knowledge : free from concealment
an open, notorious, continuous, and adverse use of the property
an open and obvious danger
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
: not restricted to a particular group or category of participants
specifically
: enterable by a registered voter regardless of political affiliation
an open primary
3
a
: 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
: not repressed or regulated by legal controls
a state with open gambling
open
2 of 2 verb
opened; opening
1
: to begin the process of
open the succession
2
a
: 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)
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
1
: to begin action : commence on some course or activity
the stock opened at par
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.
J. H. Friedenthal et al.Love words? Need even more definitions?
Merriam-Webster unabridged
Share