disk
noun
• US spelling of disc, also widely used in computing contexts.
disc
noun
• a flat, thin circular object.
• "coins were made by striking a blank disc of metal"
• an object or part resembling a disc in shape or appearance.
• "the smudged yellow disc of the moon"
Origin:
mid 17th century (originally referring to the seemingly flat circular form of the sun or moon): from French disque or Latin discus (see discus).