noun (n)

• the states'-rights doctrine that a state can refuse to recognize or to enforce a federal law passed by the United States Congress(noun.cognition)

  source: wordnet30
• the act of nullifying; making null and void; counteracting or overriding the effect or force of something(noun.act)

  Synonym:
  override
  

  source: wordnet30
• The act of nullifying; a rendering void and of no effect, or of no legal effect.(noun)

  source: webster1913