a. The science and art of diagnosing and treating disease or injury and maintaining health.b. The branch of this science encompassing treatment by drugs, diet, exercise, and other nonsurgical means.2. The practice of medicine.3. A substance, especially a drug, used to treat the signs and symptoms of a disease, condition, or injury.4. Something that serves as a remedy or corrective: medicine for rebuilding the economy; measures that were harsh medicine.5.a. Shamanistic practices or beliefs, especially among Native Americans.b. Something, such as a ritual practice or sacred object, believed to control natural or supernatural powers or serve as a preventive or remedy.