If there is a risk of something unpleasant, there is a possibility that it will happen.

If something that you do is a risk, it might have unpleasant or undesirable results.

If you say that something or someone is a risk, you mean they are likely to cause harm.

If you are considered a good risk, a bank or shop thinks that it is safe to lend you money or let you have goods without paying for them at the time.

If you risk something unpleasant, you do something which might result in that thing happening or affecting you.

If you risk doing something, you do it, even though you know that it might have undesirable consequences.

If you risk your life or something else important, you behave in a way that might result in it being lost or harmed.

To be at risk means to be in a situation where something unpleasant might happen.

If you do something at the risk of something unpleasant happening, you do it even though you know that the unpleasant thing might happen as a result.

If you tell someone that they are doing something at their own risk, you are warning them that, if they are harmed, it will be their own responsibility.

If you run the risk of doing or experiencing something undesirable, you do something knowing that the undesirable thing might happen as a result.