Modulus of elasticity means:

ELASTIC MODULUS (YOUNG’S MODULUS OR MODULUS OF ELASTICITY) The word stiffness should come to mind upon reading one of these three terms in the dental literature. Elastic modulus describes the relative stiffness or rigidity of a material, which is measured by the slope of the elastic region of the stress-strain graph. Reference: PHILLIPS’ SCIENCE OF DENTAL MATERIALS, 12th ed page no 53