Triplicate ratio

from The Collaborative International Dictionary of English v.0.48

Triplicate \Trip"li*cate\, a. [L. triplicatus, p. p. of
   triplicare to triple, treble; tri- (see {Tri-}) + plicare to
   fold. See {Ply}, v. t.]
   Made thrice as much; threefold; tripled.
   [1913 Webster]

   {Triplicate ratio} (Math.), the ratio of the cubes of two
      quantities; thus, the triplicate ratio of a to b is a^{3}:
      b^{3}.
      [1913 Webster]