The Collaborative International Dictionary of English v.0.48:

Impolite \Im`po*lite"\, a. [L. impolitus unpolishied, pref. im-
   not + politus, p. p. of polire to polish, refine. See
   Polite.]
   Not polite; not of polished manners; wanting in good manners;
   discourteous; uncivil; rude. -- Im`po*lite"ly, adv. --
   Im`po*lite"ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

impolite
    adj 1: not polite [ant: polite]

Moby Thesaurus II by Grady Ward, 1.0:

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