Definition of Homogeneous Mixture: A mixture which has uniform composition and properties throughout. For example, air is a homogeneous mixture of gases. A teaspoonful of table salt stirred into a glass of water also makes a homogeneous mixture.efinition of Homogeneous Catalyst: A catalyst that exists in the same phase as the reactants-usually liquid phase reactions, sometimes gas phase. Definition of Homogeneous Equilibrium: A reaction equilibrium in which the reactants and products are all in the same phase.