Annul

an;nul pronunciation: function: transitive verb inflected form(s): an;nulled; an;nul;lingetymology: middle english annullen, from anglo-french annuller, from late latin annullare, from latin ad- + nullus not any — more at nulldate: 15th century 1 : to reduce to nothing : obliterate2 : to make ineffective or inoperative : neutralize lt;annul the drug's effectgt;3 : to declare or make legally invalid or void lt;wants the marriage annulledgt;synonyms see nullify