1A large constellation (the Serpent) on the celestial equator, said to represent the snake coiled around Ophiuchus. It is divided into two parts by Ophiuchus, Serpens Caput (the ‘head’) and Serpens Cauda (the ‘tail’).

1. 1.1as genitive Serpentis /səːˈpɛntɪs/ Used with preceding letter or numeral to designate a star in the constellation Serpens.
   the star Beta Serpentis