The Collaborative International Dictionary of English v.0.48:

Uncivil \Un*civ"il\, a.
   1. Not civilized; savage; barbarous; uncivilized.
      [1913 Webster]

            Men can not enjoy the rights of an uncivil and of a
            civil state together.                 --Burke.
      [1913 Webster]

   2. Not civil; not complaisant; discourteous; impolite; rude;
      unpolished; as, uncivil behavior.
      [1913 Webster]

WordNet (r) 3.0 (2006):

uncivil
    adj 1: lacking civility or good manners; "want nothing from you
           but to get away from your uncivil tongue"- Willa Cather
           [syn: uncivil, rude] [ant: civil, polite]

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "uncivil":
   Gothic, Neanderthal, animal, barbarian, barbaric, barbarous,
   bestial, brutal, brutish, coarse, crass, crude, discourteous,
   disrespectful, ill-bred, ill-mannered, impertinent, impolite,
   inaffable, insolent, noncivilized, outlandish, primitive,
   rough-and-ready, rude, savage, troglodytic, unaccommodating,
   uncivilized, uncombed, uncomplaisant, uncourteous, uncourtly,
   uncouth, uncultivated, uncultured, ungallant, ungracious, unkempt,
   unlicked, unpolished, unpolite, unrefined, untamed, wild