D defs.my
Entry 4 senses Webster, 1913

Layer

/lā'-ẽr/ · Lay·er · IPA /ˈleɪ.ɚ/
01 n. One who, or that which, lays.
  1. 1.
    One who, or that which, lays.
  2. 2.
    That which is laid; a stratum; a bed; one thickness, course, or fold laid over another; as, a layer of clay or of sand in the earth; a layer of bricks, or of plaster; the layers of an onion.
  3. 3.
    A shoot or twig of a plant, not detached from the stock, laid under ground for growth or propagation.
  4. 4.
    An artificial oyster bed.