/ Dictionary / Index S sinistral: Meaning and Definition of Find definitions for: sin•is•tral Pronunciation: (sin'u-strul), [key] — adj. of, pertaining to, or on the left side; left (opposed to dextral). left-handed. (of certain gastropod shells) coiling counterclockwise, as seen from the apex. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: sinistral (Thesaurus) sinister sinistrality Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language