>racist [noun]

>A person who believes a particular race is superior to others. A person with a prejudiced belief that one race is superior to others.

No where does it mention this new-age "prejudice + power" redefinition.

The word is race + -ism, IE literally "doctrine/practice based on race". The word has nothing to do with power. A black dude in America who chooses to beat up a white dude for his race is racist, even under the assumption he is a systematically oppressed minority.