neutralise

verb

1. 1

   make chemically neutral

   She neutralized the solution

2. 2

   make ineffective by counterbalancing the effect of

   Her optimism neutralizes his gloom

   This action will negate the effect of my efforts

3. 3

   make incapable of military action

4. 4

   get rid of (someone who may be a threat) by killing

   The mafia liquidated the informer

   the double agent was neutralized