German-Polish border river
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">german-polish border river</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for oder that I've seen before include "Rode around the European river" , "German banker" , "River forming northern part of the German-Polish border" , "East European river" , "Polish/German river" .)