Rode around the river (4)
I believe the answer is:
oder
'river' is the definition.
(River Oder in central Europe)
'rode around' is the wordplay.
'around' is an anagram indicator.
'rode' with letters rearranged gives 'ODER'.
'the' acts as a link.
(Other definitions for oder that I've seen before include "German banker" , "river, one in central Europe" , "waterway" , "River on border of Poland and Germany" , "School blazer insignia" .)