Elasticity isn't flexibility, those two are completely different physical properties:
Wikipedia on elasticity: In Physics, elasticity is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed.
Wikipedia on flexbility: Stiffness is the extent to which an object resists deformation in response to an applied force. The complementary concept is flexibility or pliability: the more flexible an object is, the less stiff it is.
Wikipedia on elasticity: In Physics, elasticity is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed.
Wikipedia on flexbility: Stiffness is the extent to which an object resists deformation in response to an applied force. The complementary concept is flexibility or pliability: the more flexible an object is, the less stiff it is.