1. [n]  an act that has disastrous consequences
2. [n]  an event resulting in great loss and misfortune; "the whole city was affected by the irremediable calamity"; "the earthquake was a disaster"
3. [n]  a state of extreme (usually irremediable) ruin and misfortune; "lack of funds has resulted in a catastrophe for our school system"; "his policies were a disaster"

DISASTER is a 8 letter word that starts with D.

1. \Dis*as"ter\, n. [F. d['e]sastre; pref. d['e]s- (L.
   dis-) + astre star, fr. L. astrum; a word of astrological
   origin. See {Aster}, {Astral}, {Star}.]
   1. An unpropitious or baleful aspect of a planet or star;
      malevolent influence of a heavenly body; hence, an ill
      portent. [Obs.]
   
            Disasters in the sun.                 --Shak.
   
   2. An adverse or unfortunate event, esp. a sudden and
      extraordinary misfortune; a calamity; a serious mishap.
   
            But noble souls, through dust and heat, Rise from
            disaster and defeat The stronger.     --Longfellow.
   
   Syn: Calamity; misfortune; mishap; mischance; visitation;
        misadventure; ill luck. See {Calamity}.
   
   

2. \Dis*as"ter\, v. t.
   1. To blast by the influence of a baleful star. [Obs.] --Sir
      P. Sidney.
   
   2. To bring harm upon; to injure. [R.] --Thomson.