THESAURUS
clincher
KO, conclusive argument, coup de grace, crusher, death stroke, deathblow, end-all, ender, final stroke, finisher, finishing stroke, floorer, kayo, kayo punch, knockdown argument, knockout, knockout blow, last dab, quietus, settler, sockdolager, stopper, trump
ROGET THESAURUS
clincher
Confutation
N
confutation, refutation, answer, complete answer, disproof, conviction, redargution, invalidation, exposure, exposition,
clincher, retort, reductio ad absurdum, knock down argument, tu quoque argument, sockdolager, correction, dissuasion, confuting, confuted capable of refutation, refutable, confutable, defeasible, contravene (counter evidence), condemned on one's own showing, condemned out of one's own mouth, the argument falls to the ground, cadit quaestio, it does not hold water, suo sibi gladio hunc jugulo, his argument was demolished by new evidence.