Which term refers to a catalyst that aids in curing the adhesive?

The term "Hardener" refers to a catalyst that aids in curing an adhesive. In the context of adhesives, a hardener works by initiating the chemical reaction that causes the adhesive to set or cure, transforming it from a viscous liquid state into a solid form. This is crucial in applications where durable bonds are needed, as the hardener ensures that the adhesive achieves its desired strength and performance characteristics.

While "additive," "activator," and "solvent" may also be relevant terms in the context of adhesives, they do not specifically refer to a substance that catalyzes curing. Additives are used to enhance properties, activators are substances that can accelerate certain reactions but are not typically used in the curing process of adhesives, and solvents are used to dissolve other substances or to adjust viscosity, but they do not catalyze the curing of the adhesive. Therefore, hardener is the most accurate term that specifically corresponds to the function described in the question.