departmentn.[F. dpartement, fr. dpartir. See Depart, v. i.]1. Act of departing; departure.()Sudden departments from one extreme to another. (Wotton.)2. A part, portion, or subdivision.()3. A distinct course of life, action, study, or the like; appointed sphere or walk; province.()Superior to Pope in Pope's own peculiar department of literature. (Macaulay.)4. Subdivision of business or official duty; especially, one of the principal divisions of executive government; as, the treasury department; the war department; also, in a university, one of the divisions of instruction; as, the medical department; the department of physics.()5. A territorial division; a district; esp., in France, one of the districts composed of several arrondissements into which the country is divided for governmental purposes; as, the Department of the Loire.()6. A military subdivision of a country; as, the Department of the Potomac.()