dys·to·ni·a (dĭs-tō'nē-ə) n. Abnormal tonicity of muscle, characterized by prolonged, repetitive muscle contractions that may cause twisting or jerking movements of the body or a body part. dys·ton'ic (-tŏn'ĭk) adj.
Main Entry: dys·to·nia Pronunciation: dis-'tO-nE-& Function: noun : a state of disordered tonicity of tissues (as of muscle) —dys·ton·ic/-'tän-ik/adjective