Source : Webster's Revised Unabridged Dictionary (1913)

Elasticity \E`las*tic"i*ty\, n. [Cf. F. ['e]lasticit['e].]
   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}.

   {Surface of elasticity} (Geom.), 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.

Source : WordNet®

coefficient of elasticity
     n : (physics) the ratio of the applied stress to the change in
         shape of an elastic body [syn: {modulus of elasticity}, {elastic
         modulus}]