The resistance to deformation, that is, the tendency to resume its original shape, of a material subjected to a static or dynamic load. Strain increases as a function of stress; at rupture it represents the maximum strength of the material, usually measured in pounds per square inch or kilograms per square centimeter. The relationship of stress to strain is indicated by a curve obtained by stretching a sample of standard dimensions in a device designed for that purpose.See Stress; Modulus of Elasticity.