disk (n.)

1660s, "round, approximately flat surface," from Latin discus "quoit, discus, disk," from Greek diskos "disk, quoit, platter," related to dikein "to throw" (see discus).

The American English preferred spelling; also see disc. From 1803 as "thin, circular plate;" sense of "phonograph disk" is by 1888; computing sense is from 1947. Disk jockey first recorded 1941; dee-jay is from 1955; DJ is by 1961; video version veejay is from 1982. Disk-drive is from 1952.