A bureaucratic arm of the executive branch tasked with enforcing laws of a particular area of American life
Explanation:
The government is divided into different departments where each department focuses on a specific area of American Life and enforce laws related to that aspect of life
For eg: education department, finance department etc.
Each department has it's own senates and they have the authority to enforce laws and supervise the activities happening in that area of American life. They deal with their own area of expertise.