disk / disk/ (also disc) • n. 1. a flat, thin, round object: heavy metal disks the size of hockey pucks | onion soup ladled over a disk of cheese. ∎  an information storage device for a computer in the shape of a round flat plate that can be rotated to give access to all parts of the surface. The data may be stored either magnetically (in a magnetic disk) or optically (in an optical disk such as a CD-ROM). ∎  (disc) short for compact disc. ∎  (disc) dated a phonograph record. ∎  (discs) one of the suits in some tarot packs, corresponding to coins in others.2. a shape or surface that is round and flat in appearance: the smudged yellow disk of the moon.3. a roundish, flattened part in an animal or plant, in particular: ∎  (disc or in·ter·ver·te·bral disc) a layer of cartilage separating adjacent vertebrae in the spine: he suffered a prolapsed disc. ∎  Bot. (in a composite flowerhead of the daisy family) a close-packed cluster of disk florets in the center, forming the yellow part of the flowerhead.• v. [trans.] cultivate (a field) with a disk harrow.DERIVATIVES: disk·less adj.

disk An item of storage medium in the form of a circular plate. These devices are at present (1995) principally magnetic disks, in which the information is stored via magnetic encoding. See also optical disk, magneto-optic storage.

disk Form of computer data storage. Disks come in many different forms, some using magnetic methods to store data, such as the hard disk, while others use optical systems like the compact disc (CD) and CD-ROM.

disk var. of DISC.