Definition of "disaster"

disaster

/dɪˈzɑːs.tə(ɹ)/

noun
countable and uncountable, plural disasters
1. An unexpected natural or man-made catastrophe of substantial extent causing significant physical damage or destruction, loss of life or sometimes permanent change to the natural environment.
  Quotations
  Floods in northern India, mostly in the small state of Uttarakhand, have wrought disaster on an enormous scale. The early, intense onset of the monsoon on June 14th swelled rivers, washing away roads, bridges, hotels and even whole villages. Rock-filled torrents smashed vehicles and homes, burying victims under rubble and sludge.
  2013 June 29, “High and wet”, in The Economist, volume 407, number 8842, page 28
2. An unforeseen event causing great loss, upset or unpleasantness of whatever kind.
  Quotations
  And no use for anyone to tell Charles that this was because the Family was in mourning for Mr Granville Darracott […]: Charles might only have been second footman at Darracott Place for a couple of months when that disaster occurred, but no one could gammon him into thinking that my lord cared a spangle for his heir.
  1959, Georgette Heyer, chapter 1, in The Unknown Ajax
  A nod means good, two nods; very good. And then there's the pursing of the lips: disaster.
  2003, The Devil Wears Prada
3. A skateboard trick involving a 180-degree ollie, landing on the center of the board with the front trucks facing towards the ramp and the back trucks over the lip. The skater then leans forwards to return in the ramp.