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]