The Collaborative International Dictionary of English v.0.48:

Defame \De*fame"\, n.
   Dishonor. [Obs.] --Chaucer.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Defame \De*fame"\, v. t. [imp. & p. p. Defamed; p. pr. & vb.
   n. Defaming.] [OE. defamen, diffamen, from F. diffamer, or
   OF. perh. defamer, fr. L. diffamare (cf. defamatus infamous);
   dis- (in this word confused with de) + fama a report. See
   Fame.]
   1. To harm or destroy the good fame or reputation of; to
      disgrace; especially, to speak evil of maliciously; to
      dishonor by slanderous reports; to calumniate; to asperse.
      [1913 Webster]

   2. To render infamous; to bring into disrepute.
      [1913 Webster]

            My guilt thy growing virtues did defame;
            My blackness blotted thy unblemish'd name. --Dryden.
      [1913 Webster]

   3. To charge; to accuse. [R.]
      [1913 Webster]

            Rebecca is . . . defamed of sorcery practiced on the
            person of a noble knight.             --Sir W.
                                                  Scott.

   Syn: To asperse; slander; calumniate; vilify. See Asperse.
        [1913 Webster]

WordNet (r) 3.0 (2006):

defame
    v 1: charge falsely or with malicious intent; attack the good
         name and reputation of someone; "The journalists have
         defamed me!" "The article in the paper sullied my
         reputation" [syn: defame, slander, smirch, asperse,
         denigrate, calumniate, smear, sully, besmirch]

Moby Thesaurus II by Grady Ward, 1.0:

39 Moby Thesaurus words for "defame":
   asperse, attaint, bad-mouth, belie, bespatter, blacken, blot,
   blow upon, brand, calumniate, cast aspersions on,
   cast reflections on, censure, defile, denigrate, disapprove,
   disparage, expose, expose to infamy, gibbet, hang in effigy, libel,
   malign, misrepresent, pillory, reprimand, scandalize, slander,
   slur, smear, soil, stain, stigmatize, sully, taint, tarnish,
   throw mud at, traduce, vilify



The Devil's Dictionary (1881-1906):

DEFAME, v.t.  To lie about another.  To tell the truth about another.