Source : Webster's Revised Unabridged Dictionary (1913)

Catastrophic \Cat`a*stroph"ic\, a.
   Of a pertaining to a catastrophe. --B. Powell.

Source : WordNet®

catastrophic
     adj : extremely harmful; bringing physical or financial ruin; "a
           catastrophic depression"; "catastrophic illness"; "a
           ruinous course of action" [syn: {ruinous}]