The Collaborative International Dictionary of English v.0.48:

Efface \Ef*face"\, v. t. [imp. & p. p. Effaced; p. pr. & vb.
   n. Effacing.] [F. effacer; pref. es- (L. ex) + face face;
   prop., to destroy the face or form. See Face, and cf.
   Deface.]
   1. To cause to disappear (as anything impresses or inscribed
      upon a surface) by rubbing out, striking out, etc.; to
      erase; to render illegible or indiscernible; as, to efface
      the letters on a monument, or the inscription on a coin.
      [1913 Webster]

   2. To destroy, as a mental impression; to wear away.
      [1913 Webster]

            Efface from his mind the theories and notions
            vulgarly received.                    --Bacon.

   Syn: To blot out; expunge; erase; obliterate; cancel;
        destroy. -- Efface, Deface. To deface is to injure
        or impair a figure; to efface is to rub out or destroy,
        so as to render invisible.
        [1913 Webster]

WordNet (r) 3.0 (2006):

efface
    v 1: remove completely from recognition or memory; "efface the
         memory of the time in the camps" [syn: obliterate,
         efface]
    2: make inconspicuous; "efface oneself"
    3: remove by or as if by rubbing or erasing; "Please erase the
       formula on the blackboard--it is wrong!" [syn: erase, rub
       out, score out, efface, wipe off]