n (1) The inverse of Thixotropy. The viscosity of a rheopectic material increases with time under an applied constant stress, approaching a constant value. When the stress is removed or reduced, the viscosity diminishes toward its original value. (2) A special form of thixotropic gel which possesses the property of solidifying more rapidly when sheared (stirred) very slowly than when at complete rest. It should not be confused with dilatancy. The equilibrium state of the former is a solid gel, while the latter is a liquid.