River always going in two directions (6)
I believe the answer is:
severn
'river' is the definition.
(I've seen this before)
'always going in two directions' is the wordplay.
'two directions' means two replacements for 'direction'.
'always' becomes 'ever' (synonyms).
'going in' is an insertion indicator.
'direction' becomes 'S' (S is an example).
'direction' becomes 'n' (N is an example).
's'+'n'='sn'
'ever' placed into 'sn' is 'SEVERN'.
(Other definitions for severn that I've seen before include "Gloucester's river" , "Britain's longest river" , "Welsh and English river" , "UK's longest river" , "Britian's longest river" .)