How is telling someone that all words are made up, not just the ones they are angry about, not calling them on their shit in a real way? In cuts straight to the point and is undeniably factual. It can turn to more conversation on the topic if it's worth the effort. As science progresses, people make up words to explain new discoveries, so all words are made up.

Treating someone like a child that's acting like a child is how to deal with children.