cataclysmic

[ kat-uh-kliz-mik ]

/ ˌkæt əˈklɪz mɪk /

of, relating to, or resulting from a cataclysm.

of the nature of, or having the effect of, a cataclysm: cataclysmic changes.

Origin of cataclysmic

First recorded in 1850–55; cataclysm + -ic

cat·a·clys·mi·cal·ly, adverb non·cat·a·clys·mal, adjective non·cat·a·clys·mic, adjective

However: The historical record does not, it should be said, support the cataclysmic conclusion that Labour could never win again.

An Independent Scotland Will Hurt Labour |Michael Tomasky |September 17, 2014 |DAILY BEAST
Winters uses that cataclysmic event to examine the slow deterioration of communal life in the face of annihilation.

What Would You Do if the World Was Over? |William O’Connor |August 5, 2014 |DAILY BEAST
It was the cataclysmic collision of spitfire upstart performer, brilliant pop song, and cheeky music video.

Britney Spears’s ‘…Baby One More Time’ Turns 15: The Making of an Iconic Music Video |Kevin Fallon |October 23, 2013 |DAILY BEAST
It takes a cataclysmic and frightening event for the warmonger wing of the party to win the day.

The Case Against Isolation |Michael Tomasky |September 13, 2013 |DAILY BEAST

And Egyptian political life has taken, thereafter, a cataclysmic turn for the worse.

Why Egypt Has Coups … and We Don’t |Tunku Varadarajan |August 22, 2013 |DAILY BEAST
The sense of a cataclysmic disaster in death would pass and be replaced by a sense of the continuity of life.

Our Lady Saint Mary |J. G. H. Barry
The central life-fire which thus forces its path at cataclysmic intervals to the devastated surface is certainly no illusion.

Suspended Judgments |John Cowper Powys
The outrageous absurdity of the statement gave it cataclysmic force.

Officer 666 |Barton W. Currie
There was only one person on earth to whom he could confide this cataclysmic experience, and that was Alan.

Sinister Street, vol. 1 |Compton Mackenzie
It is probable that one of these cataclysmic epochs opened with the victories wrested from Russia by Japan.

Tales of Bengal |S. B. Banerjea