The Collaborative International Dictionary
Cataclysmal \Cat`a*clys"mal\, Cataclysmic \Cat`a*clys"mic\, a. Of or pertaining to a cataclysm.
Wiktionary
a. As destructive as a cataclysm.
WordNet
adj. severely destructive; "cataclysmic nuclear war"; "a cataclysmic earthquake" [syn: cataclysmic]
Usage examples of "cataclysmal".
But I doubt it, especially if the thing outside is some great event, something cataclysmal, like this tremendous sorrow of Dryfoos's.
The almost cataclysmal development of new machinery, the discovery of new materials, and the appearance of new social possibilities through the organised pursuit of material science, has given enormous and unprecedented facilities to the spirit of innovation.
Nothing short of the cataclysmal end of the world could have provided drama to match the stupendous stage-setting of that stormy sky.
You must figure the tumult suddenly striking on the unstable equilibrium of old Fletcher's planks and two chairs, -- with cataclysmal results.