Layer (noun)

1. A sheet, quantity, or thickness of material, typically one of several, covering a surface or body.
2. A person or thing that lays something, such as an egg.
3. A horizontal section of a structure or stratified deposit.

Origin:

Middle english: from old french laiier, from latin lacus, lacum "pond, pool".

Examples:

1. He spread a layer of butter on the bread.
2. The cake has five layers of chocolate sponge and four layers of cream.
3. She is a layer of the new company.
4. The archaeologist uncovered several layers of ancient history.
5. The atmosphere is composed of multiple layers of gases.