Noun
1. the outer boundary of an artifact or a material layer constituting or resembling such a boundary;
"there is a special cleaner for these surfaces""the cloth had a pattern of red dots on a white surface"2. the extended two-dimensional outer boundary of a three-dimensional object;
"they skimmed over the surface of the water""a brush small enough to clean every dental surface""the sun has no distinct surface"3. the outermost level of the land or sea;
"earthquakes originate far below the surface""three quarters of the Earth's surface is covered by water"4. a superficial aspect as opposed to the real nature of something;
"it was not what it appeared to be on the surface"5. information that has become public;
"all the reports were out in the open""the facts had been brought to the surface"6. a device that provides reactive force when in motion relative to the surrounding air; can lift or control a plane in flight