Source : Webster's Revised Unabridged Dictionary (1913)

Amplify \Am"pli*fy\, v. t. [imp. & p. p. {Amplified}; p. pr. &
   vb. n. {Amplifying}.] [F. amplifier, L. amplificare. See
   {Ample}, {-fy}.]
   1. To render larger, more extended, or more intense, and the
      like; -- used especially of telescopes, microscopes, etc.

   2. (Rhet.) To enlarge by addition or discussion; to treat
      copiously by adding particulars, illustrations, etc.; to
      expand; to make much of.

            Troilus and Cressida was written by a Lombard
            author, but much amplified by our English
            translator.                           --Dryden.

Amplify \Am"pli*fy\, v. i.
   1. To become larger. [Obs.]

            Strait was the way at first, withouten light, But
            further in did further amplify.       --Fairfax.

   2. To speak largely or copiously; to be diffuse in argument
      or description; to dilate; to expatiate; -- often with on
      or upon. --Watts.

            He must often enlarge and amplify upon the subject
            he handles.                           --South.

Source : WordNet®

amplify
     v 1: increase in size, volume or significance; "Her terror was
          magnified in her mind" [syn: {magnify}]
     2: to enlarge beyond bounds or the truth; "tended to
        romanticize and exaggerate this `gracious Old South'
        imagery" [syn: {overstate}, {exaggerate}, {overdraw}, {hyperbolize},
         {hyerbolise}, {magnify}] [ant: {understate}]
     3: exaggerate or make bigger; "The charges were inflated" [syn:
         {inflate}, {blow up}, {expand}]
     4: increase the volume of; "amplify sound"
     [also: {amplified}]