Definition of "Disk" :

noun: a flat circular plate

noun: (computer science) a memory device consisting of a flat disk covered with a magnetic coating on which information is stored

noun: sound recording consisting of a disk with a continuous groove; used to reproduce music by rotating while a phonograph needle tracks in the groove

noun: something with a round shape resembling a flat circular plate

"The moon's disk hung in a cloudless sky."

verb: draw a harrow over (land)