I'd say this is pretty good.My class came up with something like this (with a lot of help from me):
Racism is hostile or demeaning thoughts, words, and/or actions of one person or group of people directed towards another person or group of people with different physical characteristics such as skin color, stemming from the conscious or subconscious belief that the other group's physical characteristics makes them in some way inferior or subordinate to the first group.
SJW version: Anything that offends anyone.