From WordNet (r) 3.0 (2006):
neutralise
v 1: get rid of (someone who may be a threat) by killing; "The
mafia liquidated the informer"; "the double agent was
neutralized" [syn: neutralize, neutralise, liquidate,
waste, knock off, do in]
2: make incapable of military action [syn: neutralize,
neutralise]
3: make ineffective by counterbalancing the effect of; "Her
optimism neutralizes his gloom"; "This action will negate the
effect of my efforts" [syn: neutralize, neutralise,
nullify, negate]
4: make chemically neutral; "She neutralized the solution" [syn:
neutralize, neutralise]