Synonyms for Abrupt (same or very similar meaning)
WordNet sense 1 ((music) marked by or composed of disconnected parts or sounds; cut short crisply):
disconnected, staccato
WordNet sense 2 (extremely steep):
precipitous, sharp
WordNet sense 3 (having a sharp inclination):
steep
WordNet sense 4 (happening without warning or in a short space of time):
sudden
From the ODE community, based on WordNet
add/edit