The Collaborative International Dictionary of English v.0.48:

Ministerial \Min`is*te"ri*al\, a. [L. ministerialis: cf. F.
   minist['e]riel. See Minister, and cf. Minstrel.]
   [1913 Webster]
   1. Of or pertaining to ministry or service; serving;
      attendant.
      [1913 Webster]

            Enlightening spirits and ministerial flames.
                                                  --Prior.
      [1913 Webster]

   2. Of or pertaining to the office of a minister or to the
      ministry as a body, whether civil or sacerdotal.
      "Ministerial offices." --Bacon. "A ministerial measure."
      --Junius. "Ministerial garments." --Hooker.
      [1913 Webster]

   3. Tending to advance or promote; contributive. "Ministerial
      to intellectual culture." --De Quincey.
      [1913 Webster]

   The ministerial benches, the benches in the House of
      Commons occupied by members of the cabinet and their
      supporters; -- also, the persons occupying them. "Very
      solid and very brilliant talents distinguish the
      ministerial benches." --Burke.
      [1913 Webster]

   Syn: Official; priestly; sacerdotal; ecclesiastical.
        [1913 Webster]

WordNet (r) 3.0 (2006):

ministerial
    adj 1: of or relating to a minister of religion or the
           minister's office; "ministerial duties"
    2: of or relating to a government minister or ministry;
       "ministerial decree"

Moby Thesaurus II by Grady Ward, 1.0:

67 Moby Thesaurus words for "ministerial":
   abbatial, abbatical, accessory, adjuvant, administrating,
   administrative, agential, agentival, agentive, ambassadorial,
   ancillary, archiepiscopal, assistant, assisting, auxiliary,
   bureaucratic, canonical, capitular, capitulary, churchly, clerical,
   conducive, consular, diplomatic, directing, ecclesiastic,
   employable, episcopal, episcopalian, evangelistic, executive,
   facilitating, favoring, forwarding, fostering, handy, helpful,
   helping, instrumental, intermediary, managing, mediating,
   mediatorial, ministering, ministrant, nurtural, nutricial,
   official, officiating, pastoral, plenipotentiary, prelatial,
   prelatic, presiding, priest-ridden, priestish, priestly, promoting,
   rabbinic, sacerdotal, serviceable, serving, subservient,
   subsidiary, supervisory, ultramontane, useful



Bouvier's Law Dictionary, Revised 6th Ed (1856):

MINISTERIAL. That which is done under the authority of a superior; opposed
to judicial; 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.