1 sudden, hasty, quick, precipitate, snappy; unexpected, unannounced, unplanned, unforeseen, unanticipated:
The general's abrupt departure has been linked with the disappearance of a great deal of money.
2 precipitous, steep, sheer, sudden:
From the ridge there is an abrupt drop of 1000 metres into the valley.
3 curt, short, brusque, blunt, bluff, gruff, uncivil, rude, discourteous, impolite, unceremonious, snappish:
My bank manager gave me an abrupt reply when I asked for an increased overdraft.