Literally, a separation or division; hence, a separate part, or portion; a division of territory; as the departments of France.

A separate allotment or part of business; a distinct province, in which a class of duties are allotted to a particular person; as the department of state, assigned to the secretary of state; the treasury department; the department of war.

A separate station; as, the admirals had their respective departments. Nearly in this sense, during war, were used in America, the terms, Northern and Southern departments .