Source : Webster's Revised Unabridged Dictionary (1913)

Multiply \Mul"ti*ply\, v. t. [imp. & p. p. {Multiplied}; p. pr.
   & vb. n. {Multiplying}.] [F. multiplier, L. multiplicare, fr.
   multiplex manifold. See {Multitude}, {Complex}.]
   1. To increase in number; to make more numerous; to add
      quantity to.

            Impunity will multiply motives to disobedience.
                                                  --Ames.

   2. (Math.) To add (any given number or quantity) to itself a
      certain number of times; to find the product of by
      multiplication; thus 7 multiplied by 8 produces the number
      56; to multiply two numbers. See the Note under
      {Multiplication}.

   3. To increase (the amount of gold or silver) by the arts of
      alchemy. [Obs.]

   {Multiplying gear} (Mach.), gear for increasing speed.

   {Multiplying lens}. (Opt.) See under {Lens}.