1. Constant resistance to a passive movement of a limb throughout the entire range of movement, as when trying to bend a lead pipe.
2. The generalized nervous disorder marked by symptoms of trembling limbs and muscular rigidity as seen in parkinsonism (a syndrome similar to Parkinson disease; for example, as a side effect of an antipsychotic drug).

Parkinson disease: a slowly progressive neurologic disease characterized by a fixed unexpressive face, a tremor (shaking) when at rest, slowing of voluntary movements, walking with short fast steps, a peculiar posture and muscle weakness, caused by degeneration of an area of the brain called the basal ganglia, and by low production of the neurotransmitter dopamine.

Most patients are over fifty, but at least ten percent are under forty. It is also known as paralysis agitans and shaking palsy.