Cut north to find river (6)
I believe the answer is:
severn
'river' is the definition.
(I've seen this before)
'cut north' is the wordplay.
'cut' becomes 'sever' (severing is a kind of cutting).
'north' becomes 'n' ('N' can be a synonym of 'north').
'sever'+'n'='SEVERN'
'to find' is the link.
(Other definitions for severn that I've seen before include "Gloucester's river" , "River at Worcester" , "Britian's longest river" , "River of England and Wales" , "Longest UK river" .)