Definitions of layer:

• noun:   thin structure composed of a single thickness of cells
• noun:   a hen that lays eggs
• noun:   single thickness of usually some homogeneous substance
• noun:   a relatively thin sheetlike expanse or region lying over or under another
• noun:   an abstract place usually conceived as having depth

  Example: "A simile has at least two layers of meaning"

• verb:   make or form a layer

  Example: "Layer the different colored sands"

• name:  A surname (very rare: popularity rank in the U.S.: #35366)