What is racism? "Taking back words..." series part 1.

So I am working on a series dedicated to taking back some words that people have been trying to change the meaning of to suit nefarious agendas.
SOURCES:
Racism definition:
https://www.merriam-webster.com/dictionary/racism

Full comments of a very racist individual on C-Span calling for genocide.
https://www.c-span.org/video/?c4950419/user-clip-exterminate-white-people

Nazi Racism:
https://encyclopedia.ushmm.org/content/en/article/nazi-racism

NOTE: Before you say "Nobody says that..." here is a video of someone making the argument in question: https://www.youtube.com/watch?v=GOQ_9Y1W-yM