A boot disk is a commonly used term for a storage device that contains the necessary files to start up a computer system. However, there are other synonyms that can describe this particular storage device. For example, it can be referred to as a startup disk or a system disk as it contains the necessary files to start up or repair a computer system. Other synonyms for boot disk include rescue disk, emergency disk, and system repair disk. All these terms refer to the same thing - a storage device that can help bring a computer system back to life when it fails to start up or crashes unexpectedly.