1. The quality of being elastic; the inherent property in bodies by which they recover their former figure or dimensions, after the removal of external pressure or altering force; springiness; tendency to rebound; as, the elasticity of caoutchouc; the elasticity of the air.
2. Power of resistance to, or recovery from, depression or overwork. Coefficient of elasticity, the quotient of a stress (of a given kind), by the strain (of a given kind) which it produces; called also coefficient of resistance.
(Science: geometry) surface of elasticity, the pedal surface of an ellipsoid (see pedal); a surface used in explaining the phenomena of double refraction and their relation to the elastic force of the luminous ether in crystalline media.