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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Moby Thesaurus II by Grady Ward, 1.0:

126 Moby Thesaurus words for "prevention":
   Eighteenth Amendment, Prohibition Party, Volstead Act, abortion,
   anticipation, arrest, arrestation, arresting, avoidance, avoiding,
   avoiding reaction, balk, balking, ban, banning, bar, barring,
   block, blocking, check, checking, circumvention, contraband,
   control, controlling, curb, curbing, debarment, debarring,
   defense mechanism, delay, delaying, denial, determent, deterrence,
   disallowance, discouragement, dodge, duck, elusion, elusiveness,
   embargo, enjoining, equivocation, escape, estoppel, evasion,
   evasive action, evasiveness, exclusion, foiling, forbearance,
   forbiddance, forbidden fruit, forbidding, foreclosure,
   forestalling, forestallment, frustrating, frustration,
   getting around, halt, halting, hampering, hindering, hindrance,
   impedance, impeding, index, index expurgatorius,
   index librorum prohibitorum, inhibiting, inhibition, injunction,
   intercepting, interception, interdict, interdicting, interdiction,
   interdictum, jink, law, mitigating, mitigation, neutrality, no-no,
   nonintervention, noninvolvement, obstructing, obstruction,
   obviation, preclusion, prohibiting, prohibition,
   prohibitory injunction, proscribing, proscription, refraining,
   refusal, rejection, repression, restraining, restraint,
   restrictive covenants, retardation, ruling out, shunning,
   shunting off, shy, sidestep, sidetracking, slip, slowing, statute,
   stay, stop, stoppage, stopping, sumptuary laws, suppression, taboo,
   the runaround, thwarting, zigzag, zoning, zoning laws