Abruptly

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, (def 4).
contemporary examples

back in 2007, abe left his countrymen in disbelief when he abruptly threw in the towel after serving only a year in office.
j-pan’s liberal democrats win huge, but stability may prove elusive takashi yokota december 16, 2012

when asked if his daughter knew de ligonnes, deromme refused to answer and abruptly ended the conversation.
french aristocrat murder mystery dana kennedy april 24, 2011

and then, in april 2008, he abruptly took the newsletter from us and put it under thestreet.com’s umbrella.
jim cramer stock touting scandal randall lane june 27, 2010

vikram pandit, the chief executive officer of citi, abruptly resigned on tuesday, effective immediately.
citi ceo vikram pandit unexpectedly quits—let the conspiracy theories begin daniel gross, matthew zeitlin october 15, 2012

last october 28, after a cafeteria room prank, martin abruptly left the team.
richie incognito and the nfl’s nasty warrior culture robert silverman february 14, 2014

historical examples

the noises kept up for a minute or two, and then abruptly ceased.
the rover boys under canvas arthur m. winfield

then, abruptly, the round, baby-like face of the woman puckered in amazement.
within the law marvin dana

then abruptly they failed, as if the night, wearied with their importunity, had fallen upon the speakers and choked them.
bella donna robert hichens

“poor mr. stewart–that is indeed mournful; but, on the other hand–” i broke off abruptly.
in the valley harold frederic

all are oval and abruptly pointed, thick and firm in texture, turning yellow or russet brown in autumn.
trees worth knowing julia ellen rogers

adjective
sudden; unexpected
brusque or brief in speech, manner, etc; curt
(of a style of writing or speaking) making sharp transitions from one subject to another; disconnected
precipitous; steep
(botany) shaped as though a part has been cut off; truncate
(geology) (of strata) cropping out suddenly
adj.

1580s, from latin abruptus “broken off, precipitous, disconnected,” past participle of abrumpere “break off,” from ab- “off” (see ab-) + rumpere “break” (see rupture (n.)). related: abruptly; abruptness.