clincher

from WordNet (r) 3.0 (2006)

clincher
    n 1: an argument that is conclusive [syn: {clincher},
         {determiner}, {determining factor}]
    2: a point or fact or remark that settles something conclusively
       [syn: {clincher}, {decisive factor}]
    3: a tool used to clinch nails or bolts or rivets

from The Collaborative International Dictionary of English v.0.48

Clincher \Clinch"er\, n.
   1. One who, or that which, clinches; that which holds fast.
      --Pope.
      [1913 Webster]

   2. That which ends a dispute or controversy; a decisive
      argument.
      [1913 Webster]

from Moby Thesaurus II by Grady Ward, 1.0

23 Moby Thesaurus words for "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

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