You searched for: “nullification
1. The act of making something legally invalid, counteracting, or overriding the effect or force of something.
2. The act of canceling something out.
3. The refusal by a state government to allow the application of a section of federal law.
4. In U.S. history, a doctrine expounded by the advocates of extreme states' rights which held that states have the right to declare null and void any federal law that they deem unconstitutional.