The Collaborative International Dictionary of English v.0.48:

Outlaw \Out"law`\, v. t. [imp. & p. p. Outlawed; p. pr. & vb.
   n. Outlawing.] [AS. ?tlagian.]
   [1913 Webster]
   1. To deprive of the benefit and protection of law; to
      declare to be an outlaw. --Blackstone.
      [1913 Webster]

   2. To remove from legal jurisdiction or enforcement; as, to
      outlaw a debt or claim; to deprive of legal force. "Laws
      outlawed by necessity." --Fuller.
      [1913 Webster]

   3. To render illegal; to ban, prohibit, or proscribe under
      sanction of some penalty.
      [PJC]

The Collaborative International Dictionary of English v.0.48:

outlawed \outlawed\ adj.
   1. contrary to or forbidden by law; banned; illicit; as, a
      member of an outlawed political party.

   Syn: illegitimate, illicit, outlaw(prenominal), unlawful.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

outlawed
    adj 1: contrary to or forbidden by law; "an illegitimate seizure
           of power"; "illicit trade"; "an outlaw strike"; "unlawful
           measures" [syn: illegitimate, illicit, outlaw(a),
           outlawed, unlawful]

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "outlawed":
   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, prohibited, punishable, ruled out, taboo, tabooed, triable,
   unallowed, unauthorized, unconstitutional, under the ban,
   under-the-counter, under-the-table, unlawful, unlicensed,
   unofficial, unpermissible, unsanctioned, unstatutory, untouchable,
   unwarrantable, unwarranted, verboten, vetoed, wrongful