A word does not carry its meaning the way a suitcase carries clothes, packed once and opened identically everywhere. Ask instead what is done with the word. "Water!" — a request, a warning, an answer, a label on a bottle. The meaning is not hidden behind the word; it is there in the use. And if that is right, then a text that people keep using — answering it, correcting it, rewriting it — is not drifting away from its meaning. It is how the text means at all.