The Collaborative International Dictionary of English v.0.48:

Scurrilous \Scur"ril*ous\, a. [See Scurrile.]
   1. Using the low and indecent language of the meaner sort of
      people, or such as only the license of buffoons can
      warrant; as, a scurrilous fellow.
      [1913 Webster]

   2. Containing low indecency or abuse; mean; foul; vile;
      obscenely jocular; as, scurrilous language.
      [1913 Webster]

            The absurd and scurrilous sermon which had very
            unwisely been honored with impeachment. --Macaulay.
      [1913 Webster]

   Syn: Opprobrious; abusive; reproachful; insulting; insolent;
        offensive; gross; vile; vulgar; low; foul; foul-mouthed;
        indecent; scurrile; mean.
        [1913 Webster] -- Scur"ril*ous*ly, adv. --
        Scur"ril*ous*ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

scurrilous
    adj 1: expressing offensive reproach [syn: abusive,
           opprobrious, scurrilous]

Moby Thesaurus II by Grady Ward, 1.0:

97 Moby Thesaurus words for "scurrilous":
   Fescennine, Rabelaisian, abusive, atrocious, back-biting, backhand,
   backhanded, bawdy, belittling, bitchy, blasphemous, blue,
   calumniatory, calumnious, catty, censorious, coarse, comminatory,
   contemptuous, contumelious, cursing, damnatory, defamatory,
   degrading, denunciatory, deprecatory, depreciative, depreciatory,
   derisive, derisory, derogative, derogatory, detractory, dirty,
   disparaging, dysphemistic, epithetic, excommunicative,
   excommunicatory, foul, foul-mouthed, foul-spoken, foul-tongued,
   fulminatory, fulsome, gross, humiliating, imprecatory, impure,
   indecent, insolent, insulting, invective, ithyphallic, left-handed,
   lewd, libelous, licentious, low, lurid, maledictory, malign,
   minimizing, nasty, obscene, offending, offensive, opprobrious,
   outrageous, pejorative, pornographic, profane, raunchy, raw,
   ribald, ridiculing, risque, salacious, scabrous, scandalous,
   scatologic, scurrile, slanderous, slighting, smoking-room, smutty,
   sultry, truculent, unchaste, unclean, unprintable, unrepeatable,
   unspeakable, vile, vilifying, vituperative, vulgar