Meanings do change and you have to meet people where they're at. You have to understand what people mean when referring to societies or structures as socialist or capitalist. But if you don't have base definitions (and they exist) you become a slave to ignorance and manipulation. You can't critique something that cannot be defined.
Are you familiar with Prof Richard Wolff? I really didn't understand the pathology of the two until I heard his explanation. It's important because what they look like makes the distinction pretty arbitrary but when you understand what they are you get to understand the fundamentals of how economies work.