Tic disorder: A disorder characterized by the presence of tics. If both motor and vocal tics are present for more than six months, the diagnosis of Tourette syndrome may be made. Diagnosis is by observation. Treatment is not usually recommended for minor tics that are not bothersome to the patient. When treatment is desired, medication choices include the blood-pressure drugs guanfacine (brand name: Tenex) and catapres (brand name: Clonadine), or one of the atypical or older neuroleptics.