de·part·ment / diˈpärtmənt/ • n. a division of a large organization such as a government, university, business, or shop, dealing with a specific subject, commodity, or area of activity: the English department. ∎ an administrative district in France and other countries. ∎ (one's department) inf. an area of special expertise or responsibility: that's not my department. ∎ inf. the specified subject under discussion: I never thought of myself as above average in the looks department.