"Unavailable" refers to a state where something or someone cannot be accessed, reached, or obtained at a given time. This term can apply to various contexts, such as a product that is out of stock, a person who is not present, or a service that is temporarily not offered. In technology, "unavailable" often indicates that a system or application is down or experiencing issues, preventing users from accessing its features. For example, a website may show an "unavailable" message when it is undergoing maintenance or facing server problems, making it impossible for users to interact with it.