layer
nounUK /ˈleɪ.ər/
US /ˈleɪ.ɚ/
A layer is a flat piece of something that sits on top of another piece.
She put a layer of cheese on top of the pasta.
OTHER MEANINGS
2. A person or thing that lays something, such as a hen that lays eggs.
The farmer keeps a hundred layers for fresh eggs.
3. A shoot or stem of a plant used to grow a new plant.
He planted a layer from the old rose bush.
4. In computing, a part of a system that sits on top of another part.
The app uses a security layer to protect your data.