Someone who betrays his country by committing treason(noun)
WordNet. Princeton University. 2010.
Use "treasonist" in a sentence
"New York Congressman Peter King called the Times "treasonist," and suggested that Attorney General Gonzales consider prosecuting the Times, its reporters, editors, and maybe the janitors."
"Why didnt you bring it up when that treasonist POS bush was spending billions of dollars on his wars and tax breaks for the wealthy?"
"Billions of dollars spent and tens of thousands of lives lost because of that treasonist bastrd bush."