The Collaborative International Dictionary of English v.0.48:

Unauthorized \Unauthorized\
   See authorized.

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "unauthorized":
   actionable, against the law, anarchic, anarchistic, anomic, banned,
   barred, black-market, bootleg, chargeable, contraband,
   contrary to law, criminal, felonious, flawed, forbade, forbid,
   forbidden, illegal, illegitimate, illicit, impermissible,
   irregular, justiciable, lawless, nonconstitutional, nonlegal,
   nonlicit, nonpermissible, not permitted, off limits, out of bounds,
   outlaw, outlawed, prohibited, punishable, ruled out, taboo,
   tabooed, triable, unallowed, unapproved, unconstitutional,
   under the ban, under-the-counter, under-the-table, unlawful,
   unlicensed, unofficial, unpermissible, unsanctioned, unstatutory,
   untouchable, unwarrantable, unwarranted, verboten, vetoed,
   wrongful