sudden or unexpected

an abrupt departure.

curt or brusque in speech, manner, etc.

an abrupt reply.

terminating or changing suddenly

an abrupt turn in a road.

having many sudden changes from one subject to another; lacking in continuity or smoothness

an abrupt writing style.

steep; precipitous

an abrupt descent.

Botany . truncate ( def. 4 ) .

adjective

calm , kind , nice , at ease , deliberate , expansive , gradual , leisurely

adjective

blunt , brusque , crude , crusty , curt , direct , discourteous , gruff , impetuous , impolite , matter-of-fact , rough , short , snappy , snippy , uncivil , ungracious , hasty , hurried , jerky , precipitate , precipitous , quick , rushing , sudden , surprising , unanticipated , unceremonious , unexpected , unforeseen , precipitant , brief , short-spoken , bold , sheer , brisk , craggy , fast , headlong , instantaneous , jagged , rude , rugged , sharp , staccato , steep , swift , terse , tumultuous , unconnected , violent