evidence that disproves a previous claim or argument; disproof or rebuttal

to provide evidence that a claim or argument is false; to argue using the 反证法 fǎn​zhèng​fǎ method

(law) evidence produced by a party to disprove or override evidence presented by the opposing party

(logic/math) method of proof which proceeds by stating a proposition and then showing that its denial leads to a contradiction