The Collaborative International Dictionary of English v.0.48:

Prevention \Pre*ven"tion\, n. [Cf. F. pr['e]vention.]
   1. The act of going, or state of being, before. [Obs.]
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            The greater the distance, the greater the
            prevention.                           --Bacon.
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   2. Anticipation; esp., anticipation of needs or wishes;
      hence, precaution; forethought. [Obs.] --Hammond. Shak.
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   3. The act of preventing or hindering; obstruction of action,
      access, or approach; thwarting. --South.
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            Casca, be sudden, for we fear prevention. --Shak.
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   4. Prejudice; prepossession. [A Gallicism] --Dryden.
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WordNet (r) 3.0 (2006):

prevention
    n 1: the act of preventing; "there was no bar against leaving";
         "money was allocated to study the cause and prevention of
         influenza" [syn: prevention, bar]