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]

The Devil's Dictionary (1881-1906):

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