/ Dictionary / Index S Sinus Sabaeus: Meaning and Definition of Find definitions for: Si•nus Sa•bae•us Pronunciation: (sē'nus sa-bē'us, sī'-), [key] an area in the southern hemisphere and near the equator of Mars, appearing dark when viewed telescopically from the earth. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sinusoidal projection Sion Related Content Daily Word Quiz: ounterfeit Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language