A 100 MB or 250 MB portable storage medium.
A "Zip" disk, not to be confused with a "zip file", is a high-capacity, removable disk with a 100-250 megabyte capacity.
an electronic storage disk. Similar to a floppy disk, but holds 100 megabytes of information as compared to the floppy which holds about 1.5 megabytes. A ZIP drive is required to read or copy information to a ZIP disk. (Not to be confused with the PC zip compression format.)