neutralize

Concise Oxford English Dictionary © 2008 Oxford University Press:
neutralize /ˈnjuːtrəlʌɪz/ (or neutralise)

▶verb

• 1 make ineffective by applying an opposite force or effect.

• 2 make chemically neutral.

• 3 disarm (a bomb).

• 4 euphemistic kill or destroy.

– derivatives
neutralization noun,
neutralizer noun.