The Collaborative International Dictionary of English v.0.48:

Chorea \Cho*re"a\ n. [NL., fr. Gr. ? dance.] (Med.)
   St. Vitus's dance; a disease attended with convulsive
   twitchings and other involuntary movements of the muscles or
   limbs.
   [1913 Webster]

WordNet (r) 3.0 (2006):

chorea
    n 1: chorea in dogs [syn: canine chorea, chorea]
    2: any of several degenerative nervous disorders characterized
       by spasmodic movements of the body and limbs