/don' gl disk/ (Or "keY disk") A kind of dongle consisting of 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. [Jargon File] (1998-12-13)