What is the meaning of neutralize?

verb

• Make politically neutral and thus inoffensive.
  • usage: "The treaty neutralized the small republic"
• Make ineffective by counterbalancing the effect of.
  • usage: "Her optimism neutralizes his gloom"; "This action will negate the effect of my efforts"
  • synonyms: neutralise, nullify, negate
• Oppose and mitigate the effects of by contrary actions.
  • usage: "This will counteract the foolish actions of my colleagues"
  • synonyms: counteract, countervail, counterbalance
• Get rid of (someone who may be a threat) by killing.
  • usage: "The mafia liquidated the informer"; "the double agent was neutralized"
  • synonyms: neutralise, liquidate, waste, knock off, do in
• Make incapable of military action.
  • synonyms: neutralise
• Make chemically neutral.
  • usage: "She neutralized the solution"
  • synonyms: neutralise