libeler
  誹謗者;損害名譽者
  Li·bel·er n. One who libels. [Written also libeller.] “ Libelers of others.”
  ◄ ►
  libeler
       n : one who attacks the reputation of another by slander or
           libel [syn: defamer, maligner, slanderer, vilifier,
            backbiter, traducer]