What is Ministerial?

Legal Definition
That which is done under the authority of a superior; opposed to judidial; as, the sheriff is a ministerial officer bound to obey the judicial commands of the court.

2. When an officer acts in both a judicial and ministerial capacity, he may be compelled to perform ministerial acts in a particular way; but when he acts in a judicial capacity, he can only be required to proceed; the manner of doing so is left entirely to his judgment. See 2 Fairf. 377; Bac. Ab. Justices of the Peace, E; 1 Conn. 295; 3 Conn. 107; 9 Conn. 275; 12 Conn. 464; also Judicial; Mandamus; Sheriff.
-- Bouviers Law Dictionary
Legal Definition
That which is done under the authority of a superior; opposed to judicial; that which involves obedience to instructions, but demands no special discretion, judgment or skill.
See also
-- Black's Law Dictionary