Source : Webster's Revised Unabridged Dictionary (1913)

Decembrist \De*cem"brist\, n. (Russian Hist.)
   One of those who conspired for constitutional government
   against the Emperor Nicholas on his accession to the throne
   at the death of Alexander I., in December, 1825; -- called
   also {Dekabrist}.

         He recalls the history of the decembrists . . . that
         gallant band of revolutionists.          --G. Kennan.