abrupt, disconnected -- (marked by sudden changes in subject and sharp transitions; "abrupt prose")
abrupt -- (exceedingly sudden and unexpected; "came to an abrupt stop"; "an abrupt change in the weather")
abrupt, precipitous, sharp -- (extremely steep; "an abrupt canyon"; "the precipitous rapids of the upper river"; "the precipitous hills of Chinese paintings"; "a sharp drop")
abrupt -- (surprisingly and unceremoniously brusque in manner; "an abrupt reply")