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).
Origin of abrupt
First recorded in 1575–85; from Latin abruptus “broken off”(past participle of abrumpere), equivalent to ab-ab- + -rup- “break” + -tus past participle suffix
Records obtained by the Anchorage Daily News and ProPublica show the abrupt and unusual absence came after a junior state employee raised concerns about 558 text messages that Clarkson sent to her personal phone in March.
Alaska’s Attorney General on Unpaid Leave After Sending Hundreds of “Uncomfortable” Texts to a Young Colleague|by Kyle Hopkins, Anchorage Daily News|August 25, 2020|ProPublica
In May 2009, however, the president had an abrupt change of heart.
The Detainee Abuse Photos Obama Didn’t Want You To See|Noah Shachtman, Tim Mak|December 15, 2014|DAILY BEAST
Fans felt cheated by the abrupt end of a marriage seasons in the making (to Lady Mary, played by Michelle Dockery).