If an illness is curable, doctors can make it go away — the person can get better and stay better. A simple infection is often curable; some serious illnesses are curable if they are found early. The opposite is incurable: the illness cannot be cleared, even if medicine can still help the person live with it. Though actually, curable and treatable are not the same. Treatable means doctors can do something useful; curable means they can really end the illness. It is a calm, slightly formal word you will hear from doctors and in health news.