June 2009 UTC Yes that etymology does trace to linguistic literature though it s not often quoted I don t know if Poseidon is included but Mygdonia I ve seen it included with a possible meaning of swampy wet land PIE meug wet slippery the river mouths lakes there or that were there etc or so I remember Macedon on its own didn t look like much of a case and Poseidon as earthman sounds like a wild speculation but Mygdonia does seem to fit well 21 36 24