/ Dictionary / Index S sightless: Meaning and Definition of Find definitions for: sight•less Pronunciation: (sīt'lis), [key] — adj. unable to see; blind. invisible. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: sightless (Thesaurus) sighthound sightline 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