/ Dictionary / Index D disastrous: Meaning and Definition of Find definitions for: dis•as•trous Pronunciation: (di-zas'trus, -zä'strus), [key] — adj. causing great distress or injury; ruinous; very unfortunate; calamitous: The rain and cold proved disastrous to his health. foreboding disaster. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: disastrous (Thesaurus) disaster area disavow Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language