S: (n) refutation, defense, defence (the speech act of answering an attack on your assertions) "his refutation of the charges was short and persuasive"; "in defense he said the other man started it"
S: (n) confutation (the speech act of refuting conclusively)
S: (n) rebuttal (the speech act of refuting by offering a contrary contention or argument)
S: (n) reductio ad absurdum, reductio ((reduction to the absurd) a disproof by showing that the consequences of the proposition are absurd; or a proof of a proposition by showing that its negation leads to a contradiction)
S: (n) confutation (evidence that refutes conclusively)