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]

The Collaborative International Dictionary of English v.0.48:

expunging \expunging\ n.
   deletion by an act of expunging or erasing.

   Syn: expunction, erasure.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

expunging
    n 1: deletion by an act of expunging or erasing [syn:
         expunction, expunging, erasure]