undiplomatic

from WordNet (r) 3.0 (2006)

undiplomatic
    adj 1: not skilled in dealing with others [ant: {diplomatic},
           {diplomatical}]

from Moby Thesaurus II by Grady Ward, 1.0

35 Moby Thesaurus words for "undiplomatic":
      airy, brash, careless, casual, cursory, degage, disregardant,
      disregardful, easygoing, flippant, forgetful, free and easy,
      heedless, impolitic, inconsiderate, indifferent, insouciant, lazy,
      maladroit, oblivious, offhand, perfunctory, reckless, regardless,
      respectless, tactless, thoughtless, unheedful, unheeding,
      unmindful, unprepared, unready, unsolicitous, untactful,
      unthinking