Source : Webster's Revised Unabridged Dictionary (1913)

Ukase \U*kase"\, n. [F., fr. Russ. ukas'; pref. u- + kazate to
   show, to say.]
   In Russia, a published proclamation or imperial order, having
   the force of law.

Source : WordNet®

ukase
     n : an edict of the Russian tsar