n.1. the application of electric current. See electroconvulsive therapy. 2. a condition of lowered excitability of neural centers following the cutting of their connections with other neural centers. For example, spinal shock occurs when connections between the spinal cord and the brain are severed. 3. acute reduction of blood flow in the body due to failure of circulatory control or loss of blood or other bodily fluids, marked by hypotension, coldness of skin, usually tachycardia, and sometimes anxiety. 4. a sudden disturbance of equilibrium.