1595, from L.L. nullificare "to esteem lightly, despise, to make nothing," from L. nullus "not any" (see null) + root of facere "to make" (see factitious). Nullification in U.S. political sense of "a state's refusing to allow a federal law to
be enforced" is first attested 1798, in Thomas Jefferson, from L.L. nullificationem (nom. nullificatio) "a making as nothing."