Serpentarius \Ser`pen*ta"ri*us\, n.[NL., fr. L. serpens serpent.] (Astron.) A constellation on the equator, lying between Scorpio and Hercules; -- called also {Ophiuchus}. Ophiuchus \O`phi*u"chus\, n. [L., fr. Gr. ?, lit., holding a serpent; 'o`fis a serpent + ? to hold.] (Astron.) A constellation in the Northern Hemisphere, delineated as a man holding a serpent in his hands; -- called also {Serpentarius}.