In medical terminology, coronary refers to the protective ring of blood vessels surrounding the heart and supplying it with oxygen and other nutrients.
Coronary is generally used as a short term for coronary thrombosis, in other words a heart attack. Thrombosis is the act of those vessels clogging up. So cut back on the French fries and hit that exercise bike. The term coronary comes from the Latin word corona for crown, meaning king. In medieval times it was the duty of the curuner to protect the local interests of the crown, and so the term coronary was later developed by doctors to describe the way the blood vessels around the heart protected it.