Stratford river (4)
I believe the answer is:
avon
'stratford river' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for avon that I've seen before include "Former English county" , "Shakespeare was known as the Bard of . . . ." , "Casual attitude" , "River flowing through Bristol to the Severn" , "English river name in multiple use" .)