/pahr"kin seuh niz'euhm/ , n. Pathol.
a common neurologic disease believed to be caused by deterioration of the brain cells that produce dopamine, occurring primarily after the age of 60, characterized by tremors, esp. of the fingers and hands, muscle rigidity, shuffling gait, slow speech, and a masklike facial expression. Also called Parkinson's disease .
[ 1920-25; named after James Parkinson (1755-1824), English physician who first described it ]