The term "diluter" refers to a substance that minimizes the concentration of another substance in a solution. Some of the synonyms for diluter include solvent, thinner, diluent, reducing agent, diluting factor, and diluting substance. A solvent is a liquid that dissolves another substance and is normally used to dilute solids. A thinner, on the other hand, is a solvent that decreases the viscosity of a liquid. A diluent generally refers to an inactive ingredient used to dilute the strength of an active ingredient. A reducing agent is any substance that reduces the concentration of an initial substance. Diluting factor and diluting substance are terms used in analytical chemistry when preparing a solution.