Stop by English river last (6)
I believe the answer is:
endure
'last' is the definition.
(I know that last can be written as endure)
'stop by english river' is the wordplay.
'stop' becomes 'end' (synonyms).
'by' is a charade indicator (letters next to each other).
'english river' becomes 'ure' (River Ure).
'end'+'ure'='ENDURE'
(Other definitions for endure that I've seen before include "Stand" , "Persist over time" , "Put up with something" , "Go through" , "Bear without giving up" .)