Definition of: emulsion

(i·mul′shən) noun
1. A liquid mixture in which a fatty or resinous substance is suspended in minute globules, as butter in milk.
2. Any milky liquid.
3. Phot. A substance, as a silver salt, held in suspension in collodion or gelatin, and used to coat dry plates.
4. Physics A colloid system, consisting of the globules or particles of one liquid finely dispersed in another. See COLLOID [<LL emulsio, -onis <L emulgere. See EMULGENT.]