a nervous disorder in which jerking movements are caused by uncontrollable contractions of the muscles. This disorder is sometimes caused by such chemicals as mercurous nitrate, a chemical once used in the making of felt hats. The name comes from the fact that in Germany in the seventeenth century it was believed that good health for the year could be secured by anyone who danced before a statue of Saint Vitus on his feast day with dancing to excess said to have become confused with this disorder. —3rd South African unpublished Appr GLS (19.3.92)