The Collaborative International Dictionary of English v.0.48:

Palsy \Pal"sy\, n.; pl. Palsies. [OE. palesie, parlesy, OF.
   paralesie, F. paralysie, L. paralysis. See Paralysis.]
   (Med.)
   Paralysis, complete or partial. See Paralysis. "One sick of
   the palsy." --Mark ii. 3.
   [1913 Webster]

   Bell's palsy, paralysis of the facial nerve, producing
      distortion of one side of the face; -- so called from Sir
      Charles Bell, an English surgeon who described it.

   Scrivener's palsy. See Writer's cramp, under Writer.

   Shaking palsy, (Med.) paralysis agitans, a disease usually
      occurring in old people, characterized by muscular tremors
      and a peculiar shaking and tottering gait; now called
      parkinsonism, or Parkinson's disease.
      [1913 Webster +PJC]

The Collaborative International Dictionary of English v.0.48:

parkinsonism \parkinsonism\ n.
   A degenerative nervous disorder occurring mostly in persons
   older than 60 years, characterized in advanced stages by
   rhythmic muscular tremors, especially in the hands, and by
   rigidity of movement, a drooping posture, slow speech, and a
   masklike facial expression; the term designates a set of
   symptoms, and the underlying disease causing these symptoms
   is most commonly Parkinson's disease. Parkinsonism results
   from a deficiency in the neurotransmitter dopamine caused by
   degeneration of the cells producing that agent. It can be
   mitigated by chemotherapy with agents such as levodopa
   (3-hydroxy-L-tyrosine).

   Syn: paralysis agitans, Parkinson's disease, Parkinson's
        syndrome, Parkinson's, shaking palsy.
        [WordNet 1.5]

              A Mayo Clinic study finds parkinsonism, a group of
              ailments that includes Parkinson's disease, is
              three times more common than previously thought
              and men are more likely to develop it than women.
              The study, published Tuesday in the journal
              Neurology, found the lifetime risk of developing
              parkinsonism is 7.5 percent, three times higher
              than previously thought.            --UPI (Jan. 2,
                                                  1999)
        [PJC] Parkinson's

WordNet (r) 3.0 (2006):

Parkinsonism
    n 1: a degenerative disorder of the central nervous system
         characterized by tremor and impaired muscular coordination
         [syn: paralysis agitans, Parkinsonism, Parkinson's
         disease, Parkinson's syndrome, Parkinson's, shaking
         palsy]