While I agree that meanings are not derived or made-up willy-nilly, I don't entirely agree that we find meanings ready-made either. Consider the Ptolemaic versus the Copernican models. Both systems 'work' (on a purely predictive level the Ptolemaic was superior to Copernicus), and in fact since there is no privileged center in our current understanding of space, we could in fact choose either model, or even another center. Cattus multifarium deglubitur
My point is that it appears that meaning is not solely the construction of the sentient observer, nor is it entirely "out there," but may arise from the interplay of the two.