NOUN (4)

1. religious ministers collectively (especially Presbyterian);

2. building where the business of a government department is transacted;

3. a government department under the direction of a minister;

4. the work of a minister of religion;
- Example: "he is studying for the ministry"

The Collaborative International Dictionary of English v.0.48:

Ministry \Min"is*try\, n.; pl. Ministries . [L. ministerium. See
   Minister, n., and cf. Mystery a trade.]
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   1. The act of ministering; ministration; service. "With
      tender ministry." --Thomson.
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   2. Hence: Agency; instrumentality.
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            The ordinary ministry of second causes. --Atterbury.
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            The wicked ministry of arms.          --Dryden.
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   3. The office, duties, or functions of a minister, servant,
      or agent; ecclesiastical, executive, or ambassadorial
      function or profession.
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   4. The body of ministers of state; also, the clergy, as a
      body.
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   5. Administration; rule; term in power; as, the ministry of
      Pitt.
      [1913 Webster]

WordNet (r) 3.0 (2006):

ministry
    n 1: religious ministers collectively (especially Presbyterian)
    2: building where the business of a government department is
       transacted
    3: a government department under the direction of a minister
    4: the work of a minister of religion; "he is studying for the
       ministry"