Definition of Executive Department
That branch of government charged with carrying out the laws enacted by the legislature. The President is the chief executive officer of pie country and the governor is chief executive officer of a state. Used to describe that branch of the government in contrast to the other two branches; i.e. legislative and judicial. See Art. II, U.S.Const.
That's the definition of Executive Department in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.