Synonyms for Refutation (same or very similar meaning)
WordNet sense 1 (the speech act of answering an attack on your assertions):
defense, defence, defense
WordNet sense 2 (any evidence that helps to establish the falsity of something):
disproof, falsification
WordNet sense 3 (the act of determining that something is false):
falsifying, refutal
From the ODE community, based on WordNet
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