endri what is your problem?
yes i believe that this is Celtic name. not Gaelic. who celts are is the main question here.
dubh - dubok. place names in Serbia with dubok root: dubocica, dubica, dubrava...
1) A river etymology doesn't prove anything rather than Morava got named by the Celts during their invasion in the Balkans since river, mountain names tend to stick and stay relatively unchanged during time...
yes i believe that this is Celtic name. not Gaelic. who celts are is the main question here.
2) Take those Gaelic/Celtic words, from the time period it's being discussed, apply the Serbian language rules, will you end up with the modern words? I doubt...
dubh - dubok. place names in Serbia with dubok root: dubocica, dubica, dubrava...