| Noun | 1. | executive department - a federal department in the executive branch of the government of the United StatesEXEC, White House - the chief executive department of the United States government Navy Department - a former executive department of the United States government; created in 1798 and combined with the War Department in 1947 War Department - a former executive department of the United States government; created in 1789 and combined with the Navy Department in 1947 | |