Scots not great between banks of turbid river (5)
I believe the answer is:
tweed
'river' is the definition.
(river in Scotland)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for tweed that I've seen before include "Fabric; river" , "passes between English and Scottish banks" , "Twilled cloth" , "Flower on border" , "Rough material" .)