What does abrupt mean?
The definition of abrupt
Ab*rupt”, a.
Etym: [L. abruptus, p. p. of abrumpere to break off; ab + rumpere to break. See Rupture.]

1 Broken off; very steep, or craggy, as rocks, precipices, banks; precipitous; steep; as, abrupt places. “Tumbling through ricks abrupt,” Thomson.
2 Without notice to prepare the mind for the event; sudden; hasty; unceremonious. “The cause of your abrupt departure.” Shak.
3 Having sudden transitions from one subject to another; unconnected. The abrupt style, which hath many breaches. B. Jonson.
4 (Bot.)
Suddenly terminating, as if cut off. Gray.

— Sudden; unexpected; hasty; rough; curt; unceremonious; rugged; blunt; disconnected; broken.

Ab*rupt”, n.
Etym: [L. abruptum.]

An abrupt place. [Poetic] “Over the vast abrupt.” Milton.

Ab*rupt”, v. t.
To tear off or asunder. [Obs.] “Till death abrupts them.” Sir T. Browne.