To neutralize means to stop something from having an effect or to make something harmless. When scientists neutralize an acid in chemistry class, they add a base to cancel out its dangerous properties. When a soccer team neutralizes its opponent's star player, they use defensive tactics that prevent that player from scoring.

A goalkeeper neutralizes a penalty kick by blocking it. A doctor might neutralize a poison by giving an antidote. In video games, you might neutralize an enemy base by capturing it so it can no longer threaten your team.

You'll also hear neutralize used when someone stops a threat or danger. Security officers work to neutralize risks at airports. A skunk neutralizes threats by spraying a terrible smell. Notice that neutralizing doesn't always mean destroying something completely; it means making it unable to cause the problem it was causing. The acid is still there after you neutralize it in chemistry class, but it's no longer dangerous to touch.