(CNN) Kennedy Mitchum wasn't expecting much when she emailed Merriam-Webster last month, but she wanted to let the dictionary publisher know that she thought its definition of the word racism was inadequate. So she was surprised when an editor responded and even more surprised that the company agreed to update the entry. Mitchum has gotten into a lot conversations about racism and injustice where people have pointed to the dictionary to prove that they're not racist. It's happened a lot more lately as the world reacts to the death of George Floyd while in the custody of four Minneapolis police...