Nullification \Nul`li*fi*ca"tion\, n. [L. nullificatio contempt. See Nullify.]

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

Right of nullification (U. S. Hist.), 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.

Source: Webster's Revised Unabridged Dictionary (1913)