(computing, Internet) The portion of the World Wide Web that is indexed by conventional search engines.

(engineering) Unwanted radar or sonar wave reflection arising from the land or sea surface.

plural of control surface

interfacial energy

(physics) A quantized electromagnetic wave trapped at a metallic surface through interaction with the free electrons of the metal.

(mathematics) An equivalence class of parametrized surfaces in a metric space.

plural of Fréchet surface

(roofing) In SPF roofing, a condition of the foam in which the surface shows a linear course textured pattern and/or a pebbled surface. This surface is generally downwind of the sprayed polyurethane path and, if severe, unacceptable for proper coating and protection.

A form of deep diving using an umbilical that supplies air, power and communications from the surface to the diver, who wears a diving helmet. This is the traditional diving with a diving helmet and air hose.

plural of surface boundary layer