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 United States federal executive departments are the primary units of the executive branch of the federal government of the United States, and are analogous to ministries common in parliamentary or semi-presidential systems but, with the United States being a presidential system, led by a head of government separate from the head of state.