/ Dictionary / Index S sinistrous: Meaning and Definition of Find definitions for: sin•is•trous Pronunciation: (sin'u-strus), [key] — adj. ill-omened; unlucky; disastrous. sinistral; left. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sinistrorse Sinitic Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language