medicine

1. A substance which specifically promotes healing when ingested or consumed in some way.
2. A treatment or cure.
3. The study of the cause, diagnosis, prognosis and treatment of disease or illness.

   She's studying medicine at university because she wants to be a doctor in the future.

4. The profession of physicians, surgeons and related specialisms; those who practice medicine.
5. Ritual magic used, as by a medicine man, to promote a desired outcome in healing, hunting, warfare etc.
6. Among the Native Americans, any object supposed to give control over natural or magical forces, to act as a protective charm, or to cause healing.
7. Black magic, superstition.
8. A philter or love potion.
9. A physician.
10. Recreational drugs, especially alcoholic drinks.

verb

To treat with medicine.