n A thin, flat, circular plate or similar object.
n (figuratively) Something resembling a disk.
n (anatomy) An intervertebral disc
n (dated) A vinyl phonograph/gramophone record.
n (computer hardware, nonstandard) A disc - either a CD-ROM, an audio CD, a DVD or similar removable storage medium.
n (agriculture) A type of harrow.
n (botany) A ring- or cup-shaped enlargement of the flower receptacle or ovary that bears nectar or, less commonly, the stamens.
v (agriculture) To harrow.
v (aviation, of an aircraft's propeller) To move towards, or operate at, zero blade pitch, orienting the propeller blades face-on to the oncoming airstream and maximizing the drag generated by the propeller.
n (computer hardware) Ellipsis of floppy disk - removable magnetic medium or a hard disk - fixed, persistent digital storage. [(computer hardware) A removable disk used for storing digital data, measuring between 2 and 8 inches diagonally and storing between 80 KB and 240 MB.]