A Scale

1. Part of an overlapping arrangement of many small, flat and hard pieces of keratin covering the skin of an animal, particularly a fish or reptile.
2. A small piece of pigmented chitin, many of which coat the wings of a butterfly or moth to give them their color.
3. A flake of skin of an animal afflicted with dermatitis.
4. Part of an overlapping arrangement of many small, flat and hard protective layers forming a pinecone that flare when mature to release pine nut seeds.
5. The flaky material sloughed off heated metal.
6. Scale mail (as opposed to chain mail).
7. Limescale.
8. A scale insect.
9. The thin metallic side plate of the handle of a pocketknife.