13 letters · 18 points in Scrabble
noun the states'-rights doctrine that a state can refuse to recognize or to enforce a federal law passed by the United States Congress
noun the act of nullifying; making null and void; counteracting or overriding the effect or force of something
originBorrowed from Late Latin nullificatio, from nullifico, equivalent to null + -ification.
Etymology from Wiktionary, CC BY-SA 3.0