WordWeb Online

1. Get rid of (someone who may be a threat) by killing
   "the double agent was neutralised";
   - neutralize, liquidate, waste, knock off [informal], do in
    
2. Make incapable of military action
   - neutralize
    
3. Make ineffective by counterbalancing the effect of
   "Her optimism neutralises his gloom";
   - neutralize, nullify, negate
    
4. Make chemically neutral
   "She neutralised the solution";
   - neutralize
    
5. Oppose and mitigate the effects of by contrary actions
   "This will neutralise the foolish actions of my colleagues";
   - counteract, countervail, neutralize, counterbalance
    
6. Make politically neutral and thus inoffensive
   "The treaty neutralised the small republic";
   - neutralize

Derived forms: neutralising, neutralises, neutralised

Type of: alter, cancel, change, demilitarise [Brit], demilitarize, kill, modify, offset, set off, weaken