Which term refers to the action of making something void?

The term that refers to the action of making something void is "invalidate." This word specifically means to nullify or render something ineffective, usually in a legal or formal context, such as invalidating a contract or a decision. When something is invalidated, it loses its authority, legitimacy, or force, effectively making it as if it never existed in the first place.

In contrast, the other choices represent different actions. "Justify" means to provide reasons for or defend an action or belief, often by proving it to be right or reasonable. "Confirm" involves validating or verifying something, often to establish its truth or correctness. "Support" means to provide assistance, backing, or reinforcement to an idea, argument, or person. None of these terms convey the specific action of nullifying that "invalidate" encapsulates.