River making a U-bend (6)
I believe the answer is:
danube
'river' is the definition.
(Danube is an example)
'making a u-bend' is the wordplay.
'making' indicates an anagram.
'a'+'u'+'bend'='aubend'
'aubend' anagrammed gives 'DANUBE'.
(Other definitions for danube that I've seen before include "Great European river, musically blue (6)" , "Europe's musically blue river" , "Ban due (anag) - river" , "River flowing from Black Forest to Black Sea" , "5 down's river" .)