Noun
1. single thickness of usually some homogeneous substance;
"slices of hard-boiled egg on a bed of spinach"2. a relatively thin sheetlike expanse or region lying over or under another
3. an abstract place usually conceived as having depth;
"a good actor communicates on several levels""a simile has at least two layers of meaning""the mind functions on many strata simultaneously"4. a hen that lays eggs
5. thin structure composed of a single thickness of cells