1: the quality or state of being equal or equivalent 2 a: equivalence of a commodity price expressed in one currency to its price expressed in another b: equality of purchasing power established by law between different kinds of money at a given ratio 3: an equivalence between farmers' current purchasing power and their purchasing power at a selected base period maintained by government support of agricultural commodity prices 4 a: the property of an integer with respect to being odd or even <3 and 7 have the same parity>b (1): the state of being odd or even used as the basis of a method of detecting errors in binary-coded data (2):parity bit 5: the property of oddness or evenness of a quantum mechanical function 6: the symmetry of behavior in an interaction of a physical entity (as a subatomic particle) with that of its mirror image