Heading back, go for another look in river (4)
I believe the answer is:
oder
'river' is the definition.
(River Oder in central Europe)
'heading back go for another look' is the wordplay.
'heading back' shows that the letters should be reversed in order.
'go for another look' becomes 're-do' (do again or have another look at).
'redo' in reverse letter order is 'ODER'.
'in' is the link.
(Other definitions for oder that I've seen before include "River flowing into the Baltic" , "German banker" , "river, one in central Europe" , "European flower" , "Polish/German river" .)