meaning
Meaning is what a word points at — the thing you think of when you hear it.
A word by itself is just a sound or some letters; the meaning is the picture, feeling, or idea it wakes up in a mind. Two people share a meaning when the same word wakes up close-enough ideas in both of them. That is never perfect: meaning is built from each person's own experience, so it must be checked, not assumed — which is why this castle asks for plain words and named sources.