dongle-disk

dongle | = D = | donuts

dongle-disk /don'gl 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.

dongle | = D = | donuts