noun a discus; a quoit.
2. disk ·noun the whole surface of a leaf.
3. disk ·noun in owls, the space around the eyes.
4. disk ·noun a flat, circular plate; as, a disk of metal or paper.
5. disk ·noun the central part of a radiate compound flower, as in sunflower.
6. disk ·noun the circular figure of a celestial body, as seen projected of the heavens.
7. disk ·noun the anterior surface or oral area of coelenterate animals, as of sea anemones.
8. disk ·noun a circular structure either in plants or animals; as, a blood disk; germinal disk, ·etc.
9. disk ·noun a part of the receptacle enlarged or expanded under, or around, or even on top of, the pistil.
10. disk ·noun the lower side of the body of some invertebrates, especially when used for locomotion, when it is often called a creeping disk.