The Collaborative International Dictionary of English v.0.48:

Retouch \Re*touch"\, n. (Fine Arts)
   A partial reworking,as of a painting, a sculptor's clay
   model, or the like.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Retouch \Re*touch"\, v. t. [Pref. re- + touch: cf. F.
   retoucher.]
   1. To touch again, or rework, in order to improve; to revise;
      as, to retouch a picture or an essay.
      [1913 Webster]

   2. (Photog.) To correct or change, as a negative, by
      handwork.
      [1913 Webster]

WordNet (r) 3.0 (2006):

retouch
    v 1: give retouches to (hair); "retouch the roots"
    2: alter so as to produce a more desirable appearance; "This
       photograph has been retouched!" [syn: touch up, retouch]

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "retouch":
   adjust, adulterate, brighten up, brush up, cook, correct, doctor,
   fake, finish, fix, freshen, furbish, furbish up, improve, juggle,
   load, manipulate, pack, plant, polish, polish up, recondition,
   refresh, renovate, repair, restore, revive, rig, rub up, salt,
   shine, sophisticate, spruce, spruce up, stack, tamper with,
   tone up, touch up, vamp, vamp up