Journey beyond southern river (5)
I believe the answer is:
stour
'river' is the definition.
(East Anglian river)
'journey beyond southern' is the wordplay.
I cannot really understand how this works, but
'journey' could be 'tour' (touring is a kind of journeying) and 'tour' is found in the answer.
'southern' could be 's' (abbreviation) and 's' is found in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for stour that I've seen before include "River Constable painted" , "Constable country river" , "Essex/Sussex border river" , "English river" , "River - roust (anag)" .)