1. To make something useless or powerless, especially by removing its ability to act as a threat or an obstacle: The military unit planned to neutralize or to destroy a bomb because it was threatening the people in that area.

To neutralize is to reduce the effectiveness of enemy military personnel and materiel by gunfire, bombing, or by any other means.

2. To render a substance as neither an acid nor an alkaline: In order to relieve the pain in her stomach, Susan took some sodium bicarbonate to neutralize the acidic contents in her stomach.
3. To nullify the oscillation-producing voltage feedback from the output to the input of an amplifier through tube interelectrode capacitances: To neutralize is to make electrically inactive by putting both equal positive and negative parts together.

An external feedback path is used to produce at the input a voltage that is equal in magnitude but opposite in phase to that fed back through the interelectrode capacitance.