Source : Webster's Revised Unabridged Dictionary (1913)

Neutralize \Neu"tral*ize\, v. t. [imp. & p. p. {Neutralized}; p.
   pr. & vb. n. {Neutralizing}.] [Cf. F. neutraliser.]
   1. To render neutral; to reduce to a state of neutrality.

            So here I am neutralized again.       --Sir W.
                                                  Scott.

   2. (Chem.) To render inert or imperceptible the peculiar
      affinities of, as a chemical substance; to destroy the
      effect of; as, to neutralize an acid with a base.

   3. To destroy the peculiar or opposite dispositions of; to
      reduce to a state of indifference inefficience; to
      counteract; as, to neutralize parties in government; to
      neutralize efforts, opposition, etc.

            Counter citations that neutralize each other. --E.
                                                  Everett.

Source : WordNet®

neutralize
     v 1: make politically neutral and thus inoffensive; "The treaty
          neutralized the small republic"
     2: make ineffective by counterbalancing the effect of; "Her
        optimism neutralizes his gloom"; "This action will negate
        the effect of my efforts" [syn: {neutralise}, {nullify}, {negate}]
     3: oppose and mitigate the effects of by contrary actions;
        "This will counteract the foolish actions of my
        colleagues" [syn: {counteract}, {countervail}, {counterbalance}]
     4: get rid of (someone who may be a threat) by killing; "The
        mafia liquidated the informer"; "the double agent was
        neutralized" [syn: {neutralise}, {liquidate}, {waste}, {knock
        off}, {do in}]
     5: make incapable of military action [syn: {neutralise}]
     6: make chemically neutral; "She neutralized the solution"
        [syn: {neutralise}]