white supremacist

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun One who believes that white people are racially superior to others and should therefore dominate society.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An advocate of white supremacy, a person who believes that the white race is inherently superior to other races and that white people should have control over people of other races.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a person who believes that the white race is or should be supreme