If you open something such as a door, window, or lid, or if it opens, its position is changed so that it no longer covers a hole or gap.

Open is also an adjective.

If you open something such as a bottle, box, parcel, or envelope, you move, remove, or cut part of it so you can take out what is inside.

Open is also an adjective.

Open up means the same as open.

If you open something such as a book, an umbrella, or your hand, or if it opens, the different parts of it move away from each other so that the inside of it can be seen.

Open is also an adjective.

Open out means the same as open.

If you open a computer file, you give the computer an instruction to display it on the screen. [computing]

When you open your eyes or your eyes open, you move your eyelids upwards, for example when you wake up, so that you can see.

Open is also an adjective.

If you open your arms, you stretch them wide apart in front of you, usually in order to put them round someone.

If you stand or sit in an open way, the front of your body is fully exposed and you are not bending forward or at an angle to someone.

If you describe a person or their character as open, you mean they are honest and do not want or try to hide anything or to deceive anyone.

If you describe a situation, attitude, or way of behaving as open, you mean it is not kept hidden or secret.

If you are open to suggestions or ideas, you are ready and willing to consider or accept them.

If you say that a system, person, or idea is open to something such as abuse or criticism, you mean they might receive abuse or criticism because of their qualities, effects, or actions.

If you say that a fact or question is open to debate, interpretation, or discussion, you mean that people are uncertain whether it is true, what it means, or what the answer is.

If people open something such as a blocked road or a border, or if it opens, people can then pass along it or through it.

Open is also an adjective.

Open up means the same as open.

If a place opens into another, larger place, you can move from one directly into the other.

Open out means the same as open.

An open area is a large area that does not have many buildings or trees in it.

An open structure or object is not covered or enclosed.

If you open your shirt or coat, you undo the buttons or pull down the zip.

Open is also an adjective.

When a shop, office, or public building opens or is opened, its doors are unlocked and the public can go in.

Open is also an adjective.

When a public building, factory, or company opens or when someone opens it, it starts operating for the first time.

Open is also an adjective.

If something such as a meeting or series of talks opens, or if someone opens it, it begins.

If an event such as a meeting or discussion opens with a particular activity or if a particular activity opens an event, that activity is the first thing that happens or is dealt with. You can also say that someone such as a speaker or singer opens by doing a particular thing.

On the stock exchange, the price at which currencies, shares, or commodities open is their value at the start of that day's trading. [business]

When a film, play, or other public event opens, it begins to be shown, be performed, or take place for a limited period of time.

If you open an account with a bank or a commercial organization, you begin to use their services.

If an opportunity or choice is open to you, you are able to do a particular thing if you choose to.

To open opportunities or possibilities means the same as to open them up.

You can use open to describe something that anyone is allowed to take part in or accept.

If something such as an offer or job is open, it is available for someone to accept or apply for.