Source : Webster's Revised Unabridged Dictionary (1913)

Modify \Mod"i*fy\, v. t. [imp. & p. p. {Modified}; p. pr. & vb.
   n. {Modifying}.] [F. modifier, L. modificare, modificari;
   modus limit + -ficare (in comp.) to make. See {Mode}, and
   {-fy}.]
   1. To change somewhat the form or qualities of; to alter
      somewhat; as, to modify a contrivance adapted to some
      mechanical purpose; to modify the terms of a contract.

   2. To limit or reduce in extent or degree; to moderate; to
      qualify; to lower.

            Of his grace He modifies his first severe decree.
                                                  --Dryden.

Source : WordNet®

modify
     v 1: make less severe or harsh or extreme; "please modify this
          letter to make it more polite"; "he modified his views
          on same-gender marriage"
     2: add a modifier to a constituent [syn: {qualify}]
     3: cause to change; make different; cause a transformation;
        "The advent of the automobile may have altered the growth
        pattern of the city"; "The discussion has changed my
        thinking about the issue" [syn: {change}, {alter}]
     [also: {modified}]