Synonyms for Discourteous (same or very similar meaning)
WordNet sense 1 (lacking social graces):
ungraciousWordNet sense 2 (not polite):
impoliteWordNet sense 3 (marked by rude or peremptory shortness):
brusque, curtWordNet sense 4 (surprisingly and unceremoniously brusque in manner):
abruptFrom the ODE community, based on WordNetadd/edit