from
The Collaborative International Dictionary of English v.0.48
Disk \Disk\ (d[i^]sk), n. [L. discus, Gr. di`skos. See {Dish}.]
[Written also {disc}.]
1. A discus; a quoit.
[1913 Webster]
Some whirl the disk, and some the javelin dart.
--Pope.
[1913 Webster]
2. A flat, circular plate; as, a disk of metal or paper.
[1913 Webster]
3. (Astron.) The circular figure of a celestial body, as seen
projected of the heavens.
[1913 Webster]
4. (Biol.) A circular structure either in plants or animals;
as, a blood disk; germinal disk, etc.
[1913 Webster]
5. (Bot.)
(a) The whole surface of a leaf.
(b) The central part of a radiate compound flower, as in
sunflower.
(c) A part of the receptacle enlarged or expanded under,
or around, or even on top of, the pistil.
[1913 Webster]
6. (Zool.)
(a) The anterior surface or oral area of c[oe]lenterate
animals, as of sea anemones.
(b) The lower side of the body of some invertebrates,
especially when used for locomotion, when it is often
called a creeping disk.
(c) In owls, the space around the eyes.
[1913 Webster]
{Disk engine}, a form of rotary steam engine.
{Disk shell} (Zool.), any species of Discina.
[1913 Webster]