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}.

Multiply \Mul"ti*ply\, v. i.
   1. To become greater in number; to become numerous.

            When men began to multiply on the face of the earth,
            and daughters were born unto them.    --Gen. vi. 1.

   2. To increase in extent and influence; to spread.

            The word of God grew and multiplied.  --Acts xii.
                                                  24.

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

Source : WordNet®

multiply
     adv : in several ways; in a multiple manner; "they were multiply
           checked for errors" [ant: {singly}]
     v 1: combine by multiplication; "multiply 10 by 15" [ant: {divide}]
     2: combine or increase by multiplication; "He managed to
        multiply his profits" [syn: {manifold}]
     3: have young (animals); "pandas rarely breed in captivity"
        [syn: {breed}]
     4: have offspring or young; "The deer in our neighborhood
        reproduce madly"; "The Catholic Church tells people to
        procreate, no matter what their economic situation may be"
        [syn: {reproduce}, {procreate}]
     [also: {multiplied}]