| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |
| an extraordinary or unusual thing, person, or event; an exceptional example or instance. |
Parkinson's disease Par·kin·son's disease (pär'kĭn-sənz)
n.
A progressive nervous disease occurring most often after the age of 50, associated with the destruction of brain cells that produce dopamine, and characterized by muscular tremor, slowing of movement, partial facial paralysis, peculiarity of gait and posture, and weakness. Also called paralysis agitans.
| Parkinson's disease (pär'kĭn-sənz) Pronunciation Key
A progressive neurologic disease occurring most often after the age of 50, associated with the destruction of brain cells that produce dopamine. Individuals with Parkinson's disease exhibit tremors while at rest, slowing of movement, stiffening of gait and posture, and weakness. The disease is named after its discoverer, British physician and paleontologist James Parkinson (1755-1824). |
A chronic disease of the nervous system that usually strikes in late adult life, resulting in a gradual decrease in muscle control. Symptoms of the disease include shaking, weakness, and partial paralysis of the face. Certain drugs can help alleviate some of its symptoms.