That's the nature of language.

Correct.

That is also NOT the definition

So your previous statement was that a specific (unstated) way of defining Good and Evil, while paired with our typical modern worldview implied that Good and Evil didn't exist? I suppose you're almost certainly correct if that's the case, but I don't find that to be a very interesting statement. The only other way I can interpret this is as a claim that there is exactly one definition of Good and Evil, and anyone who uses a different definition is wrong, but that strikes me as an utterly foolish position.

I wasn't aware of Hume’s account of definition, but it strikes me as extremely straightforward.