The Collaborative International Dictionary of English v.0.48:

Expunge \Ex*punge"\ ([e^]ks*p[u^]nj"), v. t. [imp. & p. p.
   Expunged ([e^]ks*p[u^]njd"); p. pr. & vb. n. Expunging
   ([e^]ks*p[u^]n"j[i^]ng).] [L. expungere, expunctum, prick
   out, expunge, settle an account, execute; ex out + pungere to
   prick, puncture. See Pungent.]
   1. To blot out, as with pen; to rub out; to efface
      designedly; to obliterate; to strike out wholly; as, to
      expunge words, lines, or sentences.
      [1913 Webster]

   2. To strike out; to wipe out or destroy; to annihilate; as,
      to expunge an offense. --Sandys.
      [1913 Webster]

            Expunge the whole, or lop th' excrescent parts.
                                                  --Pope.

   Syn: To efface; erase; obliterate; strike out; destroy;
        annihilate; cancel.
        [1913 Webster]

WordNet (r) 3.0 (2006):

expunge
    v 1: remove by erasing or crossing out or as if by drawing a
         line; "Please strike this remark from the record"; "scratch
         that remark" [syn: strike, scratch, expunge,
         excise]

Moby Thesaurus II by Grady Ward, 1.0:

63 Moby Thesaurus words for "expunge":
   KO, abbreviate, abridge, annihilate, annul, black out, blot,
   blot out, blue-pencil, bowdlerize, call off, cancel, censor,
   complete, cross out, cut, dele, delete, discard, dispose of, drop,
   drop the curtain, edit, edit out, efface, end off, eradicate,
   erase, exclude, expurgate, extinguish, finalize, finish, fold up,
   get it over, get over with, get through with, give the quietus,
   kayo, kibosh, kill, knock out, obliterate, omit, perfect,
   polish off, put paid to, raze, rescind, rub out, rule out, scrag,
   scratch, scratch out, shoot down, sponge, sponge out, strike,
   strike off, strike out, void, wipe out, zap