Sightless \Sight"less\, a. 1. Wanting sight; without sight; blind. Of all who blindly creep or sightless soar. --Pope. 2. That can not be seen; invisible. [Obs.] The sightless couriers of the air. --Shak. 3. Offensive or unpleasing to the eye; unsightly; as, sightless stains. [R.] --Shak. -- {Sight"less*ly}, adv.- {Sight"less*ness}, n.