/ Dictionary / Index C calamitous: Meaning and Definition of Find definitions for: ca•lam•i•tous Pronunciation: (ku-lam'i-tus), [key] — adj. causing or involving calamity; disastrous: a calamitous defeat. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: calamitous (Thesaurus) calamite calamity Related Content Daily Word Quiz: quandary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language