What is medicine?

Dictionary.com defines medicine as "noun 1. any substance or substances used in treating disease or illness; medicament; remedy. 2. the art or science of restoring or preserving health or due physical condition, as by means of drugs, surgical operations or appliances, or manipulations: often divided into medicine proper, surgery, and obstetrics."
Medicine- a treatment that helps illnesses. (Ex: cold, fever, stomach viruses) The science or practice of the diagnosis, treatment, and prevention of disease (in technical use often taken to exclude surgery).