summons: an order to appear in person at a given place and time
order: (often plural) a command given by a superior (e.g., a military or law enforcement officer) that must be obeyed
hydrocephalus: an abnormal condition in which cerebrospinal fluid collects in the ventricles of the brain; in infants it can cause abnormally rapid growth of the head and bulging fontanelles and a small face; in adults the symptoms are primarily neurological