The answer is solution. However, single-phase alloys are solid metal solutions, and colloidal suspensions are homogenous mixtures that are not solutions. Homogenized milk, for example, is a colloidal suspension that technically meets the definition of a homogenous mixture because the milk fats, though immiscible with the whey (the aqueous phase), are tiny beads evenly distributed through the whey, and do not separate according to density, as they do in non-homogenized milk.