Function Keys are also heavily used in the BIOS interface. Generally during the power-on self-test, BIOS access can be gained by hitting either a function key or the delete key. In the BIOS keys can have different purposes depending on the BIOS.
Freebase(0.00 / 0 votes)Rate this definition: Surfactant. Surfactants are compounds that lower the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants.
Pulmonary surfactant is a complex substance in the lungs which reduces the surface tension of water and therefore, prevents the collapse of the alveoli. Surfactant also plays a role in defending the lungs from bacteria and viruses.