neutralise neutralise /ˈnuːtrəlaɪz/

verb

1. [British] Make chemically neutral  ( neutralise [British] , neutralize )
   make chemically neutral
    She neutralized the solution
   She neutralized the solution
   
2. [British] Make ineffective by counterbalancing the effect of  ( negate , neutralise [British] , nullify , neutralize )
   make ineffective by counterbalancing the effect of
    Her optimism neutralizes his gloom
   Her optimism neutralizes his gloom
    This action will negate the effect of my efforts
   This action will negate the effect of my efforts
   
3. [British] Make incapable of military action  ( neutralise [British] , neutralize )
   make incapable of military action
   
4. [British] Get rid of (someone who may be a threat) by killing  ( neutralise [British] , neutralize , waste , do in , knock off [Informal] , liquidate )
   get rid of (someone who may be a threat) by killing
    The mafia liquidated the informer
   The mafia liquidated the informer
    The double agent was neutralized
   the double agent was neutralized