e·las·tic·i·ty 
(ĭ-lă-stĭsĭ-tē, ē′lă-)
(ĭ-lă-stĭsĭ-tē, ē′lă-)n.
1. The condition or property of being elastic; flexibility.
2. Physics
a. The property of returning to an initial form or state following deformation.
b. The degree to which this property is exhibited.
3. A measure of how changes in price affect supply or demand for a given good, equal to the percentage of change in supply or demand divided by the percentage of the price change.