n.1 a separate part of a complex whole, esp.: a a branch of municipal or State administration (Housing Department; Department of Social Security). b a branch of study and its administration at a university, school, etc. (the physics department). c a specialized section of a large store (hardware department).
2 colloq. an area of special expertise.
3 an administrative district in France and other countries.
Phrases and idioms:
department store a large shop stocking many varieties of goods in different departments.
Etymology: F d{eacute}partement (as DEPART)