Abrupt, a.
Etymology: [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.)
2 more senses
Suddenly terminating, as if cut off. Gray.
Syn. -- Sudden; unexpected; hasty; rough; curt; unceremonious; rugged; blunt; disconnected; broken.
2 other Webster entries under this spelling
Abrupt, n.
An abrupt place. [Poetic] "Over the vast abrupt." Milton.
Abrupt, v. t.
To tear off or asunder. [Obs.] "Till death abrupts them." Sir T. Browne.
Shades of meaning
Fernald has no entry of its own for abrupt; he lists it under bluff, steep.
Where he writes about it:
A sharp ascent or descent is one that makes a sudden, decided angle with the plane from which it starts; a sheer ascent or descent is perpendicular, or nearly so; precipitous applies to that which is of the nature of a precipice, and is used especially of a descent; abrupt is as if broken sharply off, and applies to either acclivity or declivity. — from steep