[{"Bold_text": "adjective", "List Items": ["adhering to a policy of opportunism; practicing opportunism.", "Pathology.(of a microorganism) causing disease only under certain conditions, as when a person's immune system is impaired.(of a disease or infection) caused by such an organism:Pneumocystis pneumonia is an opportunistic disease that often strikes victims of AIDS.", "(of a microorganism) causing disease only under certain conditions, as when a person's immune system is impaired.", "(of a disease or infection) caused by such an organism:Pneumocystis pneumonia is an opportunistic disease that often strikes victims of AIDS."]}]