Pronunciation: (mu-tas'tu-sīz"),[key] —v.i.,-sized, -siz•ing. 1. Pathol.(of malignant cells or disease-producing organisms) to spread to other parts of the body by way of the blood or lymphatic vessels or membranous surfaces.
2. to spread injuriously: Street gangs have metastasized in our city. 3. to transform, esp. into a dangerous form: The KGB metastasized after the fall of the Soviet Union. Truth metastasized into lurid fantasy.Also,esp. Brit.,me•tas'ta•sise".