1806, from Modern Latin chorea Sancti Viti "St. Vitus dance" (originally a mass hysteria in 15c. Europe characterized by uncontrolled dancing); from Latin chorea "a dance," from Greek khoreia "dance" (see chorus). Extension to the nerve disorder is from 1620s.
choreoid cho·re·oid (kôr'ē-oid') or cho·re·i·form (kô-rē'ə-fôrm', kə-)
chorea cho·re·a (kô-rē'ə, kə-)
Irregular, spasmodic, involuntary movements of the limbs or facial muscles.