Definition - What does Cosolvent mean?
A cosolvent is a substance that is added to a mixture of two or more separate substances that are typically immiscible, in order to make them mixable. Cosolvents are added to increase the solvent power of the primary substance in the mixture.
Corrosionpedia explains Cosolvent
Cosolvents that are most used are methanol, ethanol and water. The effectiveness of a cosolvent is determined by its solubilization power. This is the maximum rate of dissolution of a solute in mixtures of various compositions. Cosolvents work best in the presence of another solvent that, in conjunction, enhances the dissolution of a solute.