verb (v)

• charge falsely or with malicious intent; attack the good name and reputation of someone(verb.communication)

  Synonym:
  asperse, besmirch, defame, denigrate, slander, smear, smirch, sully
  

  source: wordnet30
• To accuse falsely and maliciously of a crime or offense, or of something disreputable; to slander; to libel.(verb)

  source: webster1913
• To propagate evil reports with a design to injure the reputation of another; to make purposely false charges of some offense or crime.(verb)

  source: webster1913