Final answer:
Elasticity is the ability of a material to deflect and return back to its original shape. Materials that exhibit elasticity return to their original shape after deformation until stress exceeds the elastic limit.
Step-by-step explanation:
The ability of a material to deflect and return back to its original shape is called elasticity. Elasticity is the tendency of solid objects and materials to return to their original shape after the external forces (load) causing a deformation are removed. When stress is gradually increased beyond the elastic limit, the material undergoes plastic deformation and does not return to its original shape.