What property describes a material's ability to regain its original shape after deformation?

The property that describes a material's ability to regain its original shape after deformation is elasticity. Elasticity refers to the capacity of a material to undergo deformation under stress and return to its original dimensions once the stress is removed. This characteristic is fundamental in materials science and engineering, as it determines how materials respond to forces and how they can be used in structural applications.

When a material exhibits elastic behavior, it means that it can absorb energy when deformed and release that energy when returning to its initial shape. This property is essential for applications where materials must endure repeated loading and unloading without permanent deformation.

In contrast, toughness refers to a material's ability to absorb energy and plastically deform without fracturing, while malleability describes a material's capacity to deform under compressive stress, often resulting in a change in shape without breaking. Stiffness relates to a material's resistance to elastic deformation when a force is applied. These properties serve different purposes in material selection and engineering design but do not specifically relate to the ability to regain shape after being deformed, which is why elasticity is the correct answer.