Nullification /(?)/

Nul·li·fi·ca·tion

Nullification

n.
  1. The act of nullifying; a rendering void and of no effect, or of no legal effect.

Phrases & Compounds
Right of nullification
the right claimed in behalf of a State to nullify or make void, by its sovereign act or decree, an enactment of the general government which it deems unconstitutional.