A silver-white metallic element of the platinum group that resembles platinum; occurs in some copper and nickel ores; does not tarnish at ordinary temperatures and is used (alloyed with gold) in jewelry.
Progressive, degenerative disorder of the nervous system characterized by tremors, rigidity, bradykinesia, postural instability, and gait abnormalities; caused by a loss of neurons and a decrease of dopamine in the basal ganglia.