Actually, folks are not angry about the word racism. They are angry about power and the psychological effects of how racism is used to generate/maintain power. The dictionary does not define racism in context. It's the surrounding circumstances that give this word power. When people have the power to act on their prejudices to the point of conditioning, controlling or dominating the lives of others, then we are beyond the basic definition(s).
It's not as simple as stating that people hate or judge others based on differences. When hate is transformed to suffering we are talking about another level. We are talking about psychology, not terminology or etymology. We are talking about the ability to create reality. Everyone has the power to create their reality but we are surrounded by circumstances that threaten to destroy any sense of control we may have over our lives, esp. to feel safe, valuable and loved. When this is taken away because of race then we are no longer talking about what's in the dictionary.
In high school, I decided to stop using the word racism to describe what I experienced. I used the word imperialism, supremacy, manifest destiny, etc. My experience transcended race. It was about external power and my need to break my domestication that kept me enslaved by fear. It was never about a word but that word has the power to invade the mind, create energy, and thrive on fear and suffering. Talking about the word (racism) makes people upset and angry. They focus on the word or a simple definition without ever talking about the bigger picture. In the bigger picture, lots of people are talking but no one understands each other. This is what domestication or conditioning causes...fear and suffering.
What we really should be talking about is how to break away from the conditioning and create new realities. There is external power, the belief system we are conditioned with and there is internal power or the reality we create. Racism is just a part of the external form and freedom is just a part of the internal. Racism as a word in a dictionary has no meaning for me. It does not describe my experience and it no longer controls my reality.
For me (from my corner), the next step is creating opportunities for others to break free and create their own realities despite what is going on externally. Maybe if more people break away from the external, there will be less reason to fear or suffer.