dipsas

from The Collaborative International Dictionary of English v.0.48

Dipsas \Dip"sas\, n. [L., fr. Gr. ?, fr. ? thirst.]
   1. A serpent whose bite was fabled to produce intense thirst.
      --Milton.
      [1913 Webster]

   2. (Zool.) A genus of harmless colubrine snakes.
      [1913 Webster]