The Collaborative International Dictionary of English v.0.48:

Amend \A*mend"\ ([.a]*m[e^]nd"), v. i.
   To grow better by rectifying something wrong in manners or
   morals; to improve. "My fortune . . . amends." --Sir P.
   Sidney.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Amend \A*mend"\, v. t. [imp. & p. p. Amended; p. pr. & vb. n.
   Amending.] [F. amender, L. emendare; e (ex) + mendum,
   menda, fault, akin to Skr. minda personal defect. Cf.
   Emend, Mend.]
   To change or modify in any way for the better; as,
   (a) by simply removing what is erroneous, corrupt,
       superfluous, faulty, and the like;
   (b) by supplying deficiencies;
   (c) by substituting something else in the place of what is
       removed; to rectify.
       [1913 Webster]

             Mar not the thing that can not be amended. --Shak.
       [1913 Webster]

             An instant emergency, granting no possibility for
             revision, or opening for amended thought. --De
                                                  Quincey.
       [1913 Webster]

             We shall cheer her sorrows, and amend her blood, by
             wedding her to a Norman.             --Sir W.
                                                  Scott.
       [1913 Webster]

   To amend a bill, to make some change in the details or
      provisions of a bill or measure while on its passage,
      professedly for its improvement.
      [1913 Webster]

   Syn: To Amend, Emend, Correct, Reform, Rectify.

   Usage: These words agree in the idea of bringing things into
          a more perfect state. We correct (literally, make
          straight) when we conform things to some standard or
          rule; as, to correct proof sheets. We amend by
          removing blemishes, faults, or errors, and thus
          rendering a thing more a nearly perfect; as, to amend
          our ways, to amend a text, the draft of a bill, etc.
          Emend is only another form of amend, and is applied
          chiefly to editions of books, etc. To reform is
          literally to form over again, or put into a new and
          better form; as, to reform one's life. To rectify is
          to make right; as, to rectify a mistake, to rectify
          abuses, inadvertencies, etc.
          [1913 Webster]

WordNet (r) 3.0 (2006):

amend
    v 1: make amendments to; "amend the document"
    2: to make better; "The editor improved the manuscript with his
       changes" [syn: better, improve, amend, ameliorate,
       meliorate] [ant: aggravate, exacerbate, exasperate,
       worsen]
    3: set straight or right; "remedy these deficiencies"; "rectify
       the inequities in salaries"; "repair an oversight" [syn:
       rectify, remediate, remedy, repair, amend]

Moby Thesaurus II by Grady Ward, 1.0:

103 Moby Thesaurus words for "amend":
   acculturate, advance, ameliorate, better, blue-pencil, boost,
   bring forward, civilize, come along, come on, compensate, correct,
   develop, edify, edit, educate, elevate, emend, emendate, enhance,
   enlighten, enrich, fatten, favor, fix, forward, foster, gain,
   gain ground, get ahead, get along, give satisfaction, go ahead,
   go forward, go straight, graduate, grow better, improve,
   improve upon, lard, lift, look up, make all square,
   make an improvement, make good, make headway, make progress,
   make right, make strides, meliorate, mend, new-model, nurture,
   pay reparations, perk up, pick up, progress, promote, put right,
   put straight, put to rights, raise, re-form, recense, reclaim,
   recompense, rectify, redact, redeem, redraft, redress, refashion,
   refine upon, reform, regenerate, remedy, remodel, remunerate,
   renew, repair, requite, reshape, restore self-respect, revamp,
   revise, rework, rewrite, right, set right, set straight,
   set to rights, set up, shape up, show improvement, skyrocket,
   socialize, straighten out, take off, transfigure, transform,
   upgrade, uplift, work over