Source : Webster's Revised Unabridged Dictionary (1913)

Controversialist \Con`tro*ver"sial*ist\, n.
   One who carries on a controversy; a disputant.

         He [Johnson] was both intellectually and morally of the
         stuff of which controversialists are made. --Macaulay.

Source : WordNet®

controversialist
     n : a person who disputes; who is good at or enjoys controversy
         [syn: {disputant}, {eristic}]