dongle-disk

/dongl disk/ , n. A special floppy disk that is required in order to perform
some task. Some contain special coding that allows an application to
identify it uniquely, others are special code that does something that
normally-resident programs don't or can't. (For example, AT&T's Unix PC
would only come up in root mode with a special boot disk.) Also called a key
disk. See dongle.
