colloid /kol″oid/ [Gk, kolla, glue, eidos, form] , a state or division of matter in which large molecules or aggregates of molecules (1 to 100 nm in size) do not precipitate and are dispersed in another medium. In a suspension colloid the particles are insoluble and the medium may be solid, liquid, or gas. In an emulsion colloid the particles are usually water, and the medium is any of several complex hydrophilic, organic substances that become evenly dispersed among the particles of water. Compare solution, suspension.
