Parkinson's disease

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun 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.

from The Century Dictionary.

• noun A form of paralysis, paralysis agitans (which see, under paralysis), described by Parkinson in 1817.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun neurology, pathology A chronic neurological disorder resulting in lack of control over movement; poor balance and coordination; and similar symptoms.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a degenerative disorder of the central nervous system characterized by tremor and impaired muscular coordination