n. A separate part or division of a complex whole; a distinct branch or province; a subdivision, as of a class or group of activities, organizations, or the like: as, the various departments of life, knowledge, science, business, etc.; the departments of an army or a factory.n. A division of official duties or functions; a branch of government; a distinct part of a governmental organization: as, the legislative, executive, and judicial departments; the Department of State, of the Treasury, etc. See phrases below.n. A division of territory; one of the provinces or principal districts into which some countries are divided for governmental or other purposes, such as the departments of France and the military administrative departments of the United States: as, the department of Saône-et-Loire in France; the department of the Platte.n. A going away; departure.