What is Cabinet?

Legal Definition
The most senior appointed officers of the executive branch. Its officers are nominated by the President and then presented to the United States Senate for confirmation. A simple majority will vote to confirm or reject the nominee. Upon approval, they are sworn in and begin their respective duties.

Department of State

Department of the Treasury

Department of Defense

Department of Justice

Department of the Interior

Department of Agriculture

Department of Commerce

Department of Labor

Department of Health and Human Services

Department of Housing and Urban Development

Department of Transportation

Department of Energy

Department of Education

Department of Veterans' Affairs

Department of Homeland Security
Legal Definition
Certain officers who taken collectively make a board; as, the president's, cabinet, which is usually composed of the secretary of state, secretary of the treasury, the attorney general, and some others.

2. These officers are the advisers of the president.
-- Bouviers Law Dictionary
Legal Definition
The advisory board or council of a king or other chief executive. In the government of the United States the cabinet is composed of the secretary of state, the see-cretary of the treasury, the secretary of the interior, the secretary of war, the secretary of the navy, the secretary of agricniture, the secretary of commerce and labar, the attorney general, and the postmaster general. The select or secret council of a prince or executive government; so called from the apartment in which it was originally held. Webster.
-- Black's Law Dictionary
Legal Definition
A body of officials forming an advisory council.
-- Ballentine's Law Dictionary