open
open — verb
1. to move something, or to move, from a shut position so people can pass, see, or
to move something, or to move, from a shut position so people can pass, see, or use it.
Nina opened the kitchen window after the soup burned.
open + door/window
The gate opened slowly when the guard pressed the button.
intransitive: gate/door opens
Please open your mouth so the dentist can check your teeth.
Sam opened the car door for his grandmother.
At sunrise, the white flowers opened across the garden wall.
- open the door
- open the window
- open your mouth
- open the gate
Grammar Patterns
open + door/window/gate
[door/gate/flower] open(s)
open your mouth/eyes
Usage Note
This sense covers doors, windows, gates, mouths, eyes, and similar things that move from shut to unshut. Distinguish from sense 4, which focuses on removing a lid, wrapper, or seal to reach what is inside.
Common Mistakes
2. to remove a lid, seal, or wrapping from a box, bag, bottle, or package in order
to remove a lid, seal, or wrapping from a box, bag, bottle, or package in order to reach the things inside.
Lily opened the parcel with scissors at the kitchen table.
open + parcel/jar/packet
We opened the jar and smelled fresh peach jam.
Ben opened the lunch box during the train ride.
The nurse opened a new bandage packet beside the bed.
At home, Grandma opened the tea tin for the guests.
- open a parcel
- open a jar
- open a packet
- open a box
Grammar Patterns
open + parcel/jar/packet
open + box/bag/bottle
Usage Note
The object is usually a box, bag, bottle, jar, packet, parcel, or similar container. Distinguish from sense 3, where a door, gate, mouth, or flower moves into an open position.
Common Mistakes
3. if a business or public place opens, it begins serving people; if someone opens
if a business or public place opens, it begins serving people; if someone opens one, they start it.
The bakery opens at seven, so breakfast is easy here.
place opens at + time
A new clinic opened across from the station last month.
Our school library opens again after lunch at one.
The travel office opens late on Sundays in summer.
Mr. Patel opened a small flower shop near the temple.
open + shop/business
- open at seven
- open late
- open a clinic
- open a shop
Grammar Patterns
[shop/office/library] open(s) at + time
open + shop/business/place
Usage Note
The subject is usually a shop, office, clinic, library, museum, or similar place. With a person as subject, the object is the business or place they start; sense 6 is the ceremonial use.
Common Mistakes
4. to let people use, enter, or join something that was not available before.
to let people use, enter, or join something that was not available before.
The town opened two free water stations during last summer's heat wave.
open a service for public use
Our school opened the gym to neighbors on rainy weekends.
open + place + to + group
After the flood, workers opened one lane of the bridge at dawn.
open a road or route again
The museum opened its photo archive to students this spring.
The airline opened more seats after adding a larger plane.
open more seats or spaces
- open access to
- open the gym to neighbors
- open one lane
- open more seats
- open a help line
- make available
the closest broad equivalent, especially in neutral writing
- provide
focuses more on giving a service or chance
- launch
often used for a new service, product, or program
Grammar Patterns
open something to someone
open more seats / classes / lanes
open a place or service for public use
Usage Note
The subject is often a school, company, government, or other organization, and the object is usually a place, service, route, or opportunity. Distinguish from sense 6 (READY), where someone officially declares a building or event ready.
Common Mistakes
5. to make a file, website, or program appear on the screen so you can read or use
to make a file, website, or program appear on the screen so you can read or use it.
Lena opened the photo file to print Grandma's birthday picture.
open + file
Please open the map app before we leave the station.
open + app
Mr. Chen opened the spreadsheet during the sales meeting.
I opened the email attachment on the library computer.
open + attachment
The nurse opened Maya's record before the doctor came in.
- open a file
- open an app
- open a document
- open an attachment
- open a record
Grammar Patterns
open a file
open a program or app
open an attachment or record
Usage Note
Use this sense for digital things on a screen, not for starting the machine itself. Distinguish from sense 3 (NOT CLOSED), where you move a door, lid, or similar object.
Common Mistakes
6. to start, or to make an event, activity, or period start.
to start, or to make an event, activity, or period start.
The meeting opens at nine, so please arrive early.
intransitive: open at + time
Coach Rivera opened practice with ten minutes of stretching.
open + event with + first activity
The film opens with children running through a wet market.
A violin solo opened the awards night in Taipei.
The museum will open its winter show next Friday.
- open a meeting
- open a show
- open the season
- open with a speech
Grammar Patterns
open at + time
open with + first part
open + event/activity
Usage Note
Often used for meetings, shows, lessons, speeches, and stretches of time. Distinguish from sense 2, which is specifically about performing before the main act in a show.
Common Mistakes
7. if an important person opens a building, exhibition, or event, they officially a
if an important person opens a building, exhibition, or event, they officially announce its start.
The mayor opened the new bridge with a short speech.
officially open + building/event
Mayor Wu opened the art festival on Friday morning.
A famous writer opened the book fair in Tainan.
President Chen opened the science center before the tour began.
Last spring, Dr. Lin opened the children's hospital wing.
- open a bridge
- open a festival
- open a museum
- open an exhibition
- inaugurate
formal word for officially starting a public building or event
- launch
works for programmes and campaigns, but is broader
- dedicate
often used when a building or monument is formally presented
- close
to stop or end the event or service rather than begin it
Grammar Patterns
open + bridge/building/event
officially open + place/event
Usage Note
The subject is usually a mayor, president, royal, or other public figure, and the object is often a public building or event. Distinguish from sense 5, which is about regular business hours or starting a business.
Common Mistakes
8. to perform first in a concert or show, before the star act comes on.
to perform first in a concert or show, before the star act comes on.
A local jazz band opened for the singer in Kaohsiung.
open for + main performer
Mina's band is opening for the main band at the arena.
Last year, Ethan opened for a comedian on the night market stage.
The school choir opened for the visiting rock group.
- open for a singer
- open for a band
- open for a comedian
- open on the tour
Grammar Patterns
open for + performer
open before + main act
Usage Note
Usually followed by 'for' plus the better-known act. Unlike sense 1, the subject here is the performer who appears first, not the event itself.
Common Mistakes
open — noun
1. the outdoor space around you, especially when you are away from buildings or she
the outdoor space around you, especially when you are away from buildings or shelter.
After the tent tore, the scouts slept in the open by the river.
in the open = outdoors without cover
We ate lunch in the open while rain clouds hung over the hills.
At night, the goats were safer in the barn than out in the open.
out in the open
Without a bus stop nearby, Mia waited in the open beside the highway.
The guide warned us not to leave food out in the open near camp.
- in the open
- out in the open
- sleep in the open
- leave something out in the open
Grammar Patterns
in the open
out in the open
Usage Note
Usually appears in the fixed phrases 'in the open' or 'out in the open'. It often suggests being outside without a roof, walls, or other cover.
Common Mistakes
2. a state in which something is public and no longer hidden from other people.
a state in which something is public and no longer hidden from other people.
By noon, the secret was out in the open across the whole office.
out in the open = publicly known
Once the video reached reporters, the lie was in the open.
The couple's argument moved into the open during the parents' meeting.
move into the open
After years of rumors, the payments finally came into the open.
With the court papers online, the case was fully out in the open.
- out in the open
- come into the open
- bring into the open
- keep something in the open
- public view
a close neutral phrase for being visible to everyone
- public knowledge
emphasizes that many people already know the fact
- daylight
used figuratively in expressions like 'bring something into the daylight'
Grammar Patterns
out in the open
come into the open
be in the open
Usage Note
Most often used in phrases such as 'out in the open' and 'come into the open'. Distinguish from sense 1 (OUTDOORS), where the phrase refers to a physical place outside.
Common Mistakes
3. a sports event or similar competition that many kinds of players may enter, not
a sports event or similar competition that many kinds of players may enter, not only a small chosen group.
Luca played in the county open with older and stronger golfers.
play in + open tournament
The club will host a junior open on Saturday morning.
a junior open
After the regional open, Amy earned a place on the team.
Hundreds of players entered the national open this summer.
enter the national open
Every spring, the beach town holds an open for young surfers.
- county open
- junior open
- national open
- enter the open
- tournament
the broad general word and not necessarily open to all
- competition
very general and can refer to many kinds of contests
- championship
often sounds more formal and may suggest a top-level event
- invitational
a competition where only selected players may join
Grammar Patterns
a junior open
the national open
enter an open
Usage Note
Often follows a word naming the place, level, or age group, as in 'county open' or 'junior open'. Common in sports, especially golf, tennis, and similar tournaments.
Common Mistakes
open — adjective
1. in a position that lets people, air, or things pass because it has not been shut
in a position that lets people, air, or things pass because it has not been shut, locked, or fastened.
The back gate stood open after the delivery truck left.
be open for an unfastened barrier
An open suitcase spilled shirts across the hotel floor.
Please keep the kitchen window open while the paint dries.
keep + noun + open
Rosa noticed her coat was still open in the cold wind.
- door open
- window open
- leave open
- keep open
- coat open
- unfastened
best when something has not been tied, buttoned, or closed properly
- unlocked
only fits things that can be locked
- ajar
means slightly open rather than fully open
Grammar Patterns
be open
leave + noun + open
keep + noun + open
Usage Note
Often used after verbs like 'be', 'leave', and 'keep', and also before nouns such as 'door' or 'window'. Distinguish from sense 3, which is about spaces or things with no cover around them.
Common Mistakes
2. operating and ready to serve people, receive messages, or be used at that time.
operating and ready to serve people, receive messages, or be used at that time.
The bank is open until six on Fridays.
open until + time
Our help line stays open all night during storms.
stay open for service hours
Is this seat open, or is someone sitting here?
The online form will be open again after lunch.
- open until six
- open all night
- stay open
- seat open
- line open
- closed
not operating or not allowing people to use the service
- unavailable
broader opposite for something that cannot be used now
- out of service
used especially for phones, machines, and public facilities
Grammar Patterns
be open
open until + time
stay open
be open all night
Usage Note
Usually used after a linking verb to describe a shop, service, line, seat, or system that is currently available. Distinguish from sense 5, where 'open to' shows who may join or enter.
Common Mistakes
3. without walls, a roof, or another cover around it or over it.
without walls, a roof, or another cover around it or over it.
We ate in an open courtyard behind the old station.
open + place noun
The sheep slept in an open field beside the river.
An open fire burned near the center of the camp.
collocation: open fire
Two fishermen crossed the lake in an open boat before dawn.
- open field
- open courtyard
- open fire
- open boat
- open top
Grammar Patterns
open + place noun
open + field
open + fire
open + boat
Usage Note
Usually appears before nouns for outdoor spaces or things with no roof, lid, or enclosing sides. Distinguish from sense 1, which is about something that could be shut but is not shut now.
4. shown on a screen and ready for reading, changing, or using.
shown on a screen and ready for reading, changing, or using.
I still have your budget file open on my laptop.
have + file open
Three browser tabs were open during the video call.
Mina left the map app open while she walked downtown.
leave + app open
Can you keep the chat window open during the lesson?
- file open
- tab open
- window open
- app open
Grammar Patterns
have + file open
leave + app open
keep + window open
Usage Note
Most common with files, tabs, apps, and windows that remain visible and usable on a screen. If you mean the action of making a file visible, use verb sense 8.
Common Mistakes
5. allowing anyone, or a stated group, to enter, join, apply, or use something.
allowing anyone, or a stated group, to enter, join, apply, or use something.
The art contest is open to all high school students.
open to + group
This beach is open to the public after sunrise.
collocation: open to the public
Applications are open only to nurses with two years' experience.
The meeting is open to anyone who lives nearby.
- open to all
- open to the public
- open to applicants
- open competition
- open meeting
- accessible
emphasizes that people are allowed to enter or use something
- public
fits places or events intended for everyone
- unrestricted
formal and stresses lack of limits or barriers
- restricted
limited to certain people or conditions
- exclusive
kept for a small group rather than everyone
- closed
not allowing people to enter, join, or attend
Grammar Patterns
open to + all
open to + noun phrase
open to the public
Usage Note
This sense usually takes 'to' and names who may enter, attend, or take part. Distinguish from sense 2, where a service or place is simply operating and ready now.
Common Mistakes
6. known by other people, or expressed without trying to hide it.
known by other people, or expressed without trying to hide it.
There was open disagreement about the new fees at lunch.
open + disagreement
Lena's open support for the strike surprised the company board.
open + support
Open hostility followed the mayor through every market visit.
By June, their plan to leave was open knowledge in town.
collocation: open knowledge
- open support
- open criticism
- open hostility
- open disagreement
- open knowledge
- public
the broad everyday choice when something is known by everyone
- overt
formal and often used for feelings, acts, or opposition shown clearly
- unconcealed
formal and stresses that nothing is hidden
Grammar Patterns
open + support
open + criticism
open + hostility
open knowledge
Usage Note
Common with nouns such as 'support', 'criticism', 'hostility', and 'knowledge' when something is public rather than hidden. Distinguish from adjective sense 7, which is about being frank and willing to share thoughts.
7. willing to speak plainly about your feelings, plans, or problems instead of hidi
willing to speak plainly about your feelings, plans, or problems instead of hiding them from other people.
Maya was open about her divorce when the staff asked questions.
be open about + topic
The company was open with workers about the coming job cuts.
be open with + person
Unlike his brother, Ravi stayed open about the family debt.
At the press meeting, the coach was open about his fears.
- open about feelings
- open about money problems
- open with staff
- open and honest
- frank
direct and honest, sometimes stronger in tone
- candid
slightly more formal and common in interviews or serious talk
- upfront
informal and often used for early, clear disclosure
- forthcoming
often used when someone willingly gives information
Grammar Patterns
be open about + noun
be open about + -ing
be open with + person
Usage Note
Usually follows a linking verb and often takes 'about' for the topic or 'with' for the person listening. Distinguish from sense 6, where information itself is public rather than personally shared in a frank way.
Common Mistakes
8. still not settled, so a choice, answer, or result may change later.
still not settled, so a choice, answer, or result may change later.
The wedding date is still open until Hana confirms the hall.
be open for an undecided matter
The judge left the amount of damages open until next month.
leave + noun + open
After the storm, the final bus route question remained open for another day.
Several jobs are possible, so Mina is keeping her summer plans open.
keep + noun + open
- leave the date open
- keep your plans open
- remain open
- an open outcome
Grammar Patterns
be open
remain open
leave + noun + open
keep + noun + open
Usage Note
Most often used for plans, dates, outcomes, or legal matters that have not been fixed yet. Distinguish from sense 9, where 'open' describes the kind of question rather than an undecided issue.
Common Mistakes
9. used for a question that invites explanation or opinion instead of a fixed short
used for a question that invites explanation or opinion instead of a fixed short reply.
The nurse asked an open question about how the pain began.
open question in an interview
Mr. Lin uses open questions so shy students speak in full sentences.
open questions in teaching
On the survey, the last item was open and invited comments.
In the interview, one open question led Rosa to tell her whole story.
- open question
- open-ended question
- open response
- open survey item
- open-ended
the most common label in teaching and survey design
- free-response
common in tests and questionnaires
- closed
used for questions with fixed answer choices
- multiple-choice
specifically gives a set of prepared answers
Grammar Patterns
open question
open-ended question
open response
Usage Note
Usually comes before 'question' or similar task words in teaching, surveys, and interviews. It contrasts with questions that limit people to fixed answer choices.
Common Mistakes
10. In music, produced without stopping the string with a finger, or without using k
In music, produced without stopping the string with a finger, or without using keys or valves on the instrument.
On the guitar, play the open string before moving your finger.
open string on a guitar
Eva tuned the violin by listening to each open string.
each open string
The horn player held an open note without using the valves.
open note on a wind instrument
In this song, the last chord starts with an open A.
- open string
- open note
- open chord
- open A
Grammar Patterns
open string
open note
open chord
Usage Note
Mostly used by music teachers and players with words like 'string', 'note', or the name of a note such as 'open A'.
Common Mistakes
11. ready to listen to suggestions or unfamiliar ideas and give them a fair chance.
ready to listen to suggestions or unfamiliar ideas and give them a fair chance.
Our new principal is open to ideas from parents and teachers.
be open to + noun
After the first test failed, the team stayed open to change.
At first Dad laughed, but he became open to trying online classes.
be open to + -ing
The editor sounded open to my suggestion for a shorter ending.
- open to ideas
- open to change
- open to suggestions
- open to advice
- resistant
not wanting to accept change or advice
- closed-minded
unwilling to consider new ideas
Grammar Patterns
be open to + noun
be open to + -ing
Usage Note
Usually followed by 'to' plus ideas, advice, change, or suggestions. Distinguish from sense 12, where 'open to' introduces a danger or criticism rather than something welcomed.
Common Mistakes
12. easy to hurt, criticize, or attack because there is not enough protection.
easy to hurt, criticize, or attack because there is not enough protection.
After the leak, the minister was open to harsh criticism.
open to + criticism noun
A weak password leaves your bank account open to hackers.
leave + noun + open to + risk
Without helmets, the boys were open to serious head injury.
Once the wall fell, the town was open to attack from the north.
- open to attack
- open to criticism
- open to abuse
- open to injury
- vulnerable
the nearest everyday equivalent
- exposed
stresses lack of protection
- liable
more formal and common in set phrases such as 'liable to attack'
Grammar Patterns
be open to + danger noun
leave + noun + open to + noun
Usage Note
Usually followed by 'to' plus a risk noun such as 'attack', 'criticism', 'abuse', or 'injury'. Distinguish from sense 11, where the object after 'to' is something positively received or considered.
Common Mistakes
be an open secret
idiomSomething that many people know about even though it is supposed to be secret.
The affair between the two actors was an open secret in Hollywood.
It is an open secret that the company is planning to merge.
To open suddenly and with force, or to cause something to open in this way.
The window burst open during the storm.
Maya burst the door open with a single kick.
To create an opportunity for something to happen or be achieved.
This new policy opens the door to more foreign investment.
Learning Chinese opened the door to a new career for Diego.
To be willing to consider new ideas or opinions without judging them too quickly.
Sara tried to keep an open mind about the new proposal.
You should have an open mind when listening to different viewpoints.
To pay close attention in order to see or hear someone or something.
Keep your eyes open for any suspicious activity in the neighborhood.
Aiden kept his ears open for any mention of his lost dog.
To watch carefully for someone or something while doing other things.
Please keep an eye out for the mail carrier this morning.
Min kept an eye open for bargains while shopping at the market.
To delay making a decision so that you still have choices in the future.
Brian is keeping his options open by applying to several colleges.
She left her options open and didn't sign the contract yet.
on the open market
idiomAvailable for anyone to buy without restrictions.
The rare painting was sold on the open market for a high price.
These shares are not yet available on the open market.
an open book
idiomSomeone whose thoughts and feelings are easy to understand because they hide nothing.
Mia is an open book; she tells everyone exactly how she feels.
His life is an open book, with no secrets or hidden agendas.
An invitation to visit someone at any time without needing a specific date.
My grandmother gave me an open invitation to her house anytime.
Leaving your bike unlocked is an open invitation to thieves.
with your eyes open
idiomKnowing about the possible difficulties or risks before doing something.
Diego started the business with his eyes open to the risks.
She entered the relationship with her eyes open, aware of the challenges.
with open arms
idiomIn a very friendly and welcoming way.
The community welcomed the new family with open arms.
Sara's proposal was accepted with open arms by the committee.
Word family
Synonym discussion
Sense: verb/3
For verb/3, open is the broad everyday verb for moving something from shut to unshut: open a door, open your eyes, open the gate. Unlock is narrower: it means taking away a lock, and the door or box may still stay shut afterwards. Unfasten is used for buttons, straps, zips, and similar things that hold something closed. Undo often suggests releasing a knot, button, or other fastening, while uncover means removing something laid over the top. So you can unlock a car, then open the door; unfasten a helmet strap; or uncover a dish at dinner. A useful memory rule is: keys unlock, fingers unfasten or undo, and open is the general choice.
Common collocations
Etymology
The core idea of open is "not shut". Oxford traces the word to Old English open as an adjective and openian as a verb. Those forms came from an older Germanic family that also gave Dutch open and German offen, and they are linked to the same root as the adverb up. That history matches the basic picture of a door, lid, or cover being raised or moved away. From that physical idea, English later built wider meanings such as "ready for business", "public", and "willing to listen".