The Collaborative International Dictionary of English v.0.48:

Expurgate \Ex"pur*gate\ ([e^]ks"p[u^]r*g[=a]t or
   [e^]ks*p[^u]r"g[=a]t; 277), v. t. [imp. & p. p. Expurgated
   ([e^]ks`p[u^]r*g[=a]"t[e^]d); p. pr. & vb. n. Expurgating
   ([e^]ks`p[u^]r*g[=a]"t[i^]ng).] [L. expurgatus, p. p. of
   expurgare to purge, purify; ex out, from + purgare to
   cleanse, purify, purge. See Purge, and cf. Spurge.]
   To purify; to clear from anything noxious, offensive, or
   erroneous; to cleanse; to purge; as, to expurgate a book.
   [1913 Webster]

WordNet (r) 3.0 (2006):

expurgate
    v 1: edit by omitting or modifying parts considered indelicate;
         "bowdlerize a novel" [syn: bowdlerize, bowdlerise,
         expurgate, castrate, shorten]

Moby Thesaurus II by Grady Ward, 1.0:

50 Moby Thesaurus words for "expurgate":
   abbreviate, abridge, bleach, blot out, blue-pencil, bowdlerize,
   cancel, censor, clean, clean out, clean up, cleanse, clear out,
   cross out, cut, delete, delouse, depurate, deterge, dry-clean,
   dust, dust off, edit, edit out, erase, expunge, freshen, kill,
   lustrate, omit, purge, purify, reform, rescind, rub out, scavenge,
   spruce, steam-clean, strike, strike off, strike out, sweep out,
   sweeten, tidy, void, whiten, wipe, wipe off, wipe out, wipe up