Orb/ɔːrb/ Definition 1 of 4Pro Tip 1/2Celestial Bodies Used to describe planets, stars, and other heavenly bodies in space. Astronomers discovered a remote orb circling a distant star. Pro Tip 2/2Not Usually Humans Don't use 'orb' for things shaped like a ball that are man-made or human-related. He admired the basketball, but did not refer to it as an orb.