emulsion

Universal Words noun [C,U] 1 any mixture of liquids that do not normally mix together, such as oil and water: These saws normally use an oil / water emulsion as lubricant. 2 (also emulsion paint) (BrE) a type of paint used on walls and ceilings that dries without leaving a shiny surface: silk / matt emulsion * They gave the walls a coat of white emulsion. 3 (technical) a substance on the surface of PHOTOGRAPHIC film that makes it sensitive to light: photographic / film emulsion