• (a.) Offensive or unpleasing to the eye; unsightly; as, sightless stains. • (a.) That can not be seen; invisible. • (a.) Wanting sight; without sight; blind. Found on http://thinkexist.com/dictionary/meaning/sightless/
Sight'less adjective 1. Wanting sight; without sight; blind. « Of all who blindly creep or sightless soar.» Pope. 2. That can not be seen; invisible. [ Obsolete] « The sightless couriers of the air.» Shak. 3. Offensive... Found on http://www.encyclo.co.uk/webster/S/100