MS wrote:

RCodePaul wrote:

MS wrote:

Its disc

What to Know
Although disc and disk are listed as variants for something round and flat in shape, each one seems to have a preferred usage. Disc is seen more often in the music industry and throwable objects such as Frisbees, whereas disk is the preferred spelling in computer-related lingo such as floppy disk.

In the dictionary, disk and disc are shown as variant nouns separated by or, which means that they occur with more or less equal frequency in edited text. But there are some instances where one spelling is applied more often than the other.

Origins of 'Disc' and 'Disk'
To start from the beginning: the word derives from the Latin noun discus, which means “quoit, disk, dish.” The Greeks spelled this word as diskos, deriving it from the verb dikein (“to throw”). The diskos was a round, flat object that Greek athletes would throw for distance during the ancient Olympics, a sporting tradition that continues in the modern Olympics with the spelling discus.

The discus became a useful item of comparison for anything having a round, flat shape being called a disc or disk. But initially there was no consensus among English speakers on whether to use the Latin-derived spelling (with the c) or the Greek-derived spelling (with the k).

The word found use as a descriptive word for round heavenly bodies as viewed from the earth, as well as for objects of similar shape occurring in nature (as in the body).

…when we hastened to the shore we could detect only a ripple in the water ruffling the disk of a star.
— Henry David Thoreau, A Week on the Concord and Merrimack Rivers, 1849

His sister, to his spiritual vision, was always like the lunar disk when only a part of it is lighted.
— Henry James, The Europeans, 1878

The different segments of the coccyx are connected together by an extension downwards of the anterior and posterior sacro-coccygeal ligaments, a thin annular disc of fibro-cartilage being inte

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