To orbit is to follow a circular or elliptical path around a central body. Usually a planet, moon or satellite is described as orbiting, but a child who has too much sugar can sometimes orbit around his parents in an annoying fashion.
The FDA was empowered by the United States Congress to enforce the Federal Food, Drug, and Cosmetic Act, which serves as the primary focus for the Agency; the FDA also enforces other laws, notably Section 361 of the Public Health Service Act and associated regulations, many of which are not directly related to food or drugs.
The executive branch consists of the President, his or her advisors and various departments and agencies. This branch is responsible for enforcing the laws of the land. The judicial branch consists of the U.S. Supreme Court and the Federal Judicial Center. The Federal Judicial Center is the education and research agency for the federal courts.