How Well Do You Know English Slang?
late 14c., "one who or that lays" (especially stones, "a mason"), agent noun from lay (v.). Passive sense of "that which is laid over a surface" first recorded 1610s, but because earliest English use was in cookery, this is perhaps from French liue "binding," used of a thickened sauce. Layer cake attested from 1881.
1832, from layer (n.). Related: Layered; layering.
layer lay·er (lā'ər)
A single thickness of a material covering a surface or forming an overlying part or segment. v. lay·ered, lay·er·ing, lay·ers
To divide or form into layers.