The Collaborative International Dictionary of English v.0.48:

Prohibition \Pro`hi*bi"tion\, n. [L. prohibitio: cf. F.
   prohibition.]
   1. The act of prohibiting; a declaration or injunction
      forbidding some action; interdict.
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            The law of God, in the ten commandments, consists
            mostly of prohibitions.               --Tillotson.
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   2. Specifically, the forbidding by law of the sale of
      alcoholic liquors as beverages.
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   Writ of prohibition (Law), a writ issued by a superior
      tribunal, directed to an inferior court, commanding the
      latter to cease from the prosecution of a suit depending
      before it. --Blackstone.
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   Note: By ellipsis, prohibition is used for the writ itself.
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WordNet (r) 3.0 (2006):

writ of prohibition
    n 1: a judicial writ from a higher court ordering a lower court
         not to exercise jurisdiction in a particular case