the outer boundary of an artifact or a material layer constituting or resembling such a boundary | thin structure composed of a single thickness of cells |
a device that provides reactive force when in motion relative to the surrounding air; can lift or control a plane in flight | a hen that lays eggs |
a superficial aspect as opposed to the real nature of something | single thickness of usually some homogeneous substance |
information that has become public | an abstract place usually conceived as having depth |
the extended two-dimensional outer boundary of a three-dimensional object | a relatively thin sheetlike expanse or region lying over or under another |
the outermost level of the land or sea | |