Source : Webster's Revised Unabridged Dictionary (1913)

Jura \Ju"ra\, n. [F. & L.]
   1. A range of mountains between France and Switzerland.

   2. (Geol.) The Jurassic period. See {Jurassic}.

Jurassic \Ju*ras"sic\, a. (Geol.)
   Of the age of the middle Mesozoic, including, as divided in
   England and Europe, the Lias, O["o]lite, and Wealden; --
   named from certain rocks of the Jura mountains. -- n. The
   Jurassic period or formation; -- called also the {Jura}.

Source : WordNet®

jura
     See {jus}